Yesterday, my 6 year old daughter got home with her 2nd broken tooth. They are broken just like when you break glass or something. They are her baby teeth. One has just a little piece left on her gums and the rest of it is just gum, no whole no t=nothing. The other is half broken. WHY did this happen?

You say she got home with a broken tooth. Where was she when they got broke?
Could somebody be doing something to her that is causing her teeth to break?
If her teeth were bad I don't think they would break one at a time.

Where in her mouth are these teeth?

If they are at the front (center two top or bottom) they may just be falling out. As the adult tooth pushes into the mouth it causes the root of the baby tooth to shrink away. When the root is completely or almost completely resorbed the crown portion can crumble.

It's a good idea to take her to the dentist where they can let you know for sure. They may want to x-ray the area.

When is the last time your daughter saw a dentist? Does she brush and floss everyday? Did she fall, or get hit in the face, causing the teeth to break?

A trip to the family dentist is probably in order so she can have a full check-up, in general, your teeth should not shatter, even with trauma.

I would say that you first ask your daughter why how and where they broke... ask every detail... note the colour of the teeth if they are yellowish having uneven surface, may be your child is suffering from an anomaly of dentine or enamel... consult a dentist... he might take an o.p.g