Most parents resign themselves to the fact that they will eventually square off with their kids about something of critical importance to one or both of them. While I’m no exception, I didn’t think it would happen quite so soon.

My daughter has been drinking water out of a sippy cup for months but still takes immense comfort and pleasure in drinking milk from a bottle twice daily. However, last week at her 15-month well-child visit, the pediatrician announced it was time to wean her off the bottle, lest we risk her attending her prom while still sucking on the nipple.

The next morning I awoke to the unmistakable sounds of distress coming from downstairs as my husband tried to give our daughter milk in a sippy cup. She seemed confused then anguished and, ultimately, pissed. We quickly conferred.

“Maybe I can give her the milk in a bottle now and then later, when she gets up from her nap this afternoon, you can try to give it to her in a sippy cup again,” he pleaded as the sounds of toddler hysteria grew alarmingly louder.

“No, we have to stand firm. I’m sure in a few hours, or by tomorrow, she’ll be fine,” I yelled back over the din.

Later that day, she walked around playing it cool, deftly staring right through the milk-filled sippy cup like it was a panhandler holding out a tin can on a New York City subway.

“To hell with your milk and the sippy cup it’s in,” she seemed to be saying with her stoicism. I almost wished she’d act out because the nonchalant attitude seemed eerily sophisticated for someone with a penchant for eating paper.

The next morning her indifference turned into panic. She took one look at the milk in the foreign milk vessel and swatted it away, after which time she fell to the floor, howling, the tears streaming down her face like she’d just watched Oprah unmask the chimp woman. It was her first full-blown tantrum, actually (which has since been lovingly noted in her baby book).

That same reaction lasted another day or two until she stopped crying and started antagonizing me. She’d calmly take the sippy cup, walk around with it for a minute and then shake it upside down, seeing how much milk would spill out before dumping it on the floor and then moving on to peacefully play with her toys while I cleaned up the dairy mess.

I’m not sure if it’s a coincidence, but since she’s been banned from the bottle she’s also taken to scowling on a semi-regular basis — generally in my direction. And at other times she’s been coming up to me, wrapping her arms around my legs and looking up at me wide-eyed, cooing, “ba ba?”

Everything has become a ba ba to her (or a bachul, as it’s alternatively called). She points to a hairbrush, lamp, bathtub, the Zans can guy in “One Fish Two Fish Red Fish Blue Fish,” and whines to have it passed to her. I don’t know what’ll happen if a kid in her gym or music class whips out an actual bottle in her presence, but I can guarantee it won’t end well.

We’ve tried reading her the “Bye-Bye Bottle!” book that our friend gave us. She seems to enjoy it — dutifully identifying the bottle on each page — until it gets to the part where the toddler happily adjusts to the sippy cup. That’s when she snatches the book, tosses it aside and runs away. We’ve also tried calling it by different names (“big girl cup”) and buying different kinds of sippy cups, but her scowl each time reminds us she’s nobody’s fool.

Nearly two weeks of milk-less days into it, I’m starting to worry she might come down with the calcium equivalent of scurvy. So I’ve been researching other foods with calcium (besides cheese, because no one wants to see her undergo an angioplasty on her second birthday).

Kale is on the list, as is okra, collard greens, turnip greens, sardines, currants, prickly pears, rhubarb and spinach. It just seems a bit cruel to take away her beloved bottle and milk and replace them with sustenance that seems most appropriate for children in a Grimm’s Fairy Tale. After all, this isn’t “The Story of the Youth Who Went Forth to Learn What Fear Was.”

We plan to give it a few more days and if worse comes to worst, we’ll get a corsage for her bottle and cross our fingers hoping that her prom date is too dumb to notice or too polite to say anything.

Follow Meredith at Twitter.com/MCCarroll and e-mail questions or comments to meredithccarroll@hotmail.com.