Three years ago, when Sean Preston and Jayden James were just a twinkle in Britney Spears' un-court-monitored eye, she wrote in one her Letters of Truth, "Cooking is kind of like motherhood. To be really good at it, you don't need instructions. You kind of just go on instinct and what feels right."

And we all know how that turned out.

So we're a wee bit concerned now that her little sis, Jamie Lynn, 16, whose bombshell baby revelation to OK! still has us reeling, appears to be adopting a similarly intuitive attitude.

"I think it's something that you just know how to do," she tells OK! of the bun baking in her oven. "As your body changes and all these things happen, I think it becomes natural to know what to do."

Lynne Spears and Jamie Lynn Spears in 2006

Even more disconcerting is Jamie Lynn's conviction that she'll pick up whatever doesn't come to her through osmosis from mother Lynne, who we're guessing isn't about to sit her down for a chapter-by-chapter discussion of "What to Expect While You're Expecting" or the pros and cons of the Ferber method.

"I have a great mom and she has raised three kids, so if I take lessons from her, I think I'll be great," the "Zoey 101" starlet tells the magazine of Lynne, who has taken the brunt of the blame (rightly or wrongly -- your call) for the way her showbiz-steered offspring have turned out.

"My mom will be helping me so much," she adds. "I have to take responsibility and do a lot of it myself, but she's going to have to teach me so much."

(By the by, Britney, who, like Jamie Lynn, was apparently never schooled on that whole "actions having consequences" thing, once referred to the capriciously estranged Lynne as "Supermom" and the "best role model.")

On the plus side, says JLS, "I love babies, and I have nephews that I love ... All my friends have little brothers or sisters."

Meanwhile, an insider posits to "Access Hollywood" that Jamie Lynn still has "the mind of a teenager. She doesn't understand the ramifications. She's just a child with not a lick of sense."

What's more, she's "not thinking 10 years down the road, not even two years down the road," sighs the source. "There's no reasoning with her."

And while Jamie Lynn confesses to OK! that discovering she was pregnant came as a "complete and total shock ... I can't say it was something I was planning to do right now," a not-so-close relation offers another theory, namely, she did it deliberately to separate herself from her big sister's downward spiral drama.

"She wants a little bit of 'me' attention, with everything that's going on with Britney like it is," Chanda McGovern, the former wife of Jamie Lynn's uncle, tells the New York Post. "It may be one of the reasons she went out and did what she did, and whether she got pregnant on purpose or by accident, that's the reason she went out and rebelled."

Brit, who was said to be "frantic" over the baby news, now supposedly sees an upside to Jamie Lynn's new tabloid-topping status.

The Chicago Sun-Times reports she had a "testy" phone conversation with her enceinte sibling when she discovered OK! knew about her impending stork visit before she did.

After they hung up, the paparazzi-courting calamity purportedly turned to her assistant du jour and said, ''Well, the good news is, this will take the focus off me for a while.''

And it seems it didn't take her long to get excited about becoming an aunt.

Britney Spears and Jamie Lynn Spears at a basketball game in 2006

TMZ.com reports Britney bought her little sis a $500 gift basket from Los Angeles baby boutique Petit Tresor on Wednesday, filling it with a variety of white-hued items including a blanket, stuffed elephant, onesies, socks and sneakers, along with a note reading, "Dear J.L., We love you! Brit, Sean and Jayden."

More disturbingly, she also ordered a tank top emblazoned with the words, "Hot Mama 2 B," because that's the message you want to send to Jamie Lynn's already traumatized tween fan base.

Oy.

As for the matriarch behind the dysfunction, she shares her side of the story with OK!, recounting the fateful moment shortly before Thanksgiving when she learned she was going to be a grandma for the third time.

"She came to me and said, 'Mom, I have to tell you something. Here, it's in a note.' I was taken aback," recalls Lynne. "I read the note, which of course said that she was pregnant, and ran into the living room. I said, 'I don't believe this. This is not funny!'"

But one look at father-to-be Casey Aldridge, 18, who was "staring straight ahead," may have convinced her. "She said, 'Yes, Momma it's true,'" recollects Lynne.

As for Casey, he doesn't comment in the article, but an insider tells People that changing dirty diapers wasn't what he had in mind at this point in his young life, although he's stepping up and taking responsibility.

"He has all sorts of plans for his future. He wants to start his own business, maybe get a degree and make something of himself," the source tells the mag. "He's a stand-up guy, and he will take care of the baby. He is not the type to let her deal with it on her own. He will be there in any way he can."

But conflicting reports have surfaced over exactly how much he'll be there. Life & Style claims Jamie Lynn and Casey are nearly kaput, while "Access Hollywood" hints they are itching to get hitched.

"Jamie Lynn and Casey are NOT together. They've broken up numerous times, but he was her first and she kept taking him back," a mole alleges to L&S. "They're not dating now. He's really got nothing to offer this baby. He's a kid himself. They have no plans to get married."

But a Spears family snitch tells "Access" they "want to get married really bad," but their parents, in an apparent moment of clarity, "don't think they should. They are too young. They should wait."

Casey's pastor-uncle Odus Jackson agrees, telling People, "They may or may not [get married]. You just never know ... I hope they will stick it out and get married for the child's sake and their sake. But if they're not in love and it was just a fantasy, they don't need to make the same mistake twice."

The official word from Jamie Lynn is that a marriage discussion hasn't yet happened. "Right now, we're just focusing on the baby and having a healthy baby," she tells OK!.

Not yet burned out on Jamie Lynn's afterschool special of a life? Here are a few more revelations from the OK! interview:

She's eager to know the sex:
"I want to find out as soon as I can because I'm impatient. I just want a healthy, happy baby, so whether it's a boy or a girl really doesn't matter."

On her changing shape:
"I'm not showing, but some days I'm like, 'Wow, I feel like I'm showing today,' and Mom says, 'No, you're not. Be quiet.' It's great to have her there. She is really supportive of me."

On making like the Madonna song and keeping her baby:
"I think my whole life I would have to live with knowing what I did or what I didn't do. I'm trying to do the right thing. I think that this is what is going to make me happy in the end."

On seeing the baby at her first ultrasound:
"[Mom and Casey were there.] I was just kinda sitting there. I didn't expect to be able to see all that. Again, it was a shock. At first, everything is so shocking and you're scared. But then when I saw it, I was like, 'It's going to be OK.' It's things like that, that make you realize it'll be OK. "

Next: Katie: Tom & Nicole's Kids Call Me Mom