I'm a dentist.

First and foremost, you left out the single most important piece of information about your child: her age!

Right now, I'm wondering: "Is she a 12 hear-old who is losing her baby molars? Or is she an 18 year-old who drinks a lot of soda and has undiagnosed juvenile-onset periodontal disease who is losing her adult molars?"

Let me assume that your daughter is somewhere between the ages of 10 and 14 and she's losing her baby molars as the (adult) premolars are erupting beneath them.

There's likely nothing wrong with your daughter's mouth. As the adult teeth develop and begin to erupt, they cause resorption of the roots of the baby teeth above them. Without roots to anchor them in, the baby teeth fall out (...with a little help from wiggling fingers!!). This is a normal process. Sometimes the adult tooth can cause resorption that extends far up into the "crown" of the baby tooth (i.e. the part that is normally above the gumline). If this happens, and the crown of the baby tooth is sufficiently thinned out, it can become quite brittle and simply break! If there are any periodontal fibers still clinging to the tooth, it will remain in the mouth until she wiggles it out.

Now, there are a few far-fetched, unlikely problems that could conceivably produce this observation. Two that come to mind are amelogenesis imperfecta and dentinogenesis imperfecta. But these are two conditions that any competent dentist would have diagnosed many moons ago. Chances are, your daughter's teeth are developing and exfoliating perfectly normally.

It's quite neat how this process occurs! Watching children develop is like watching a trillion Chia-Pets grow. Kids are amazing little buggers, aren't they?