D3 biting her thumbs (not just nails, the nail AND thumb)

[zaqsert]

Although I am still "staying" with my uBPDw, it kind of feels like we are parallel parenting more and more lately.

Soon after we took away our daughter's pacifiers at age 2 (doctor's recommendation because of her teeth), she started to pick at and then bite her nails.  We have not been successful in making her stop yet.

Last night while getting her in bed, I brought over her nail clippers to clip off a piece of a nail that she had mostly bitten off, but was still hanging on.

While I was trimming her nails, I noticed that both of her thumbs (one in particular) had a nail that looked pretty deformed.  I clip her nails periodically, and this was new.  I am sure I would have noticed before.  I noticed it tonight again, and finally realized that she must be biting her thumb, which is leaving a really big indentation about half-way up her nail.  I tried talking about it with her.  She said she did not want to talk about it and asked me to stop clipping her nails.  Later on, once she was in bed, I brought it up again and tried to tell her how important it is to take care of her nails, her fingers, and all of herself.

After tucking D3 in, I went to talk with my wife.  She said she had been aware of D3 biting her thumbs and about the deformed nails.  She seemed to think nothing of it other than to say things like "I've tried to tell her to stop, I don't know what else to do."  Often when I see my wife say something to D3, it comes out somewhere along a scale of growing anger, then she says she's giving up, she gives up, and stops saying anything further, letting D3 continue whatever she was doing.

It seems to me that a good deal of D3's stress comes from my wife's behaviors and invalidation.  Over the past year or so, my wife has spent even less time with D3 than she used to.  On one hand that's sort of good -- less nasty stuff to be exposed to.  On the other hand, I can only imagine that it's stressful either way.

For one, we will probably try that nail polish for kids that tastes terrible, to try to help her stop.  But then I worry that she may develop another unhealthy coping habit.

And I worry that she is biting down so hard on her fingers to cause such damage.  I really worry if this could be an early form of cutting, even at age 3.

Has anyone experienced anything similar?  Any thoughts on what you might do if this were your D3?  I am considering taking her to her pediatrician to ask for recommendations too.