Looking up the pathophysiology, the incubation period is actually 2-7 weeks, although there may be a "latent period" (which obviously doesn't apply) for up to 6 months.
So, yes, it is entirely possible she picked it up at the hospital... but it's also spread by indirect contact. So if you've left your house at any point since she was born (grocery shopping, to the park, pediatrician office, what have you), and TOUCHED anything... the handle of the cart, sat in a chair, etc... you or your daughter could have picked it up there as well. Same token... studies have shown that 80 percent of patients have antibodies to this virus, so someone can be a carrier and you wont even know it.
Flip side of the coin, if you've had anyone over to your house or taken your daughter out of it, (yikes, just think of all the places you've been...) she's shedding virus as she goes. So where exactly she got it, or who she's already given it to... is one of those impossible things to determine.
It's a pox virus, like chicken pox or small pox, but without the pesky death and fevers attached to the others. So, while ugly and contageous, at least you've got one of the "better" ones to have.
In healthy patients, MC is generally self-limited and heals spontaneously after several months. Individual lesions are seldom present for more than 2 months. Although treatment is not required, it may help reduce autoinoculation or transmission to close contacts and improve clinical appearance.The most appropriate therapeutic approach largely depends on the clinical situation. In healthy children, a major goal is to limit discomfort, and benign neglect or minor direct lesional trauma is appropriate.
AKA... usually it's best to do nothing (benign neglect) with young children, and let it self resolve... or to remove individual lesions that are particularly painful, or troublesome. There have been a lot of studies done on the alternative treatments (since this is a reeeeally common - 1 in 6- skin condition), and it's a mixed bag of results. Medically, they ALL have side effects...some that are "worse" then the pox to begin with, so they're usually reserved for AIDS and other immunocompromised patients, that their immune system is NOT going to be able to take care of it given enough time.
Sorry.