You can hire a professional inspector to look for allergens, including mold, and other unsafe conditions at the mother's house. If necessary, you can get court order to allow the inspection. You will have to front the expense of the inspection. Make sure to hire an inspector who will give you a written report, and is willing to come to court to authenticate and explain it. You should have your own house inspected, too, just to be thorough (and you may want to hire a different inspector for your house since you don't know the results in advance).
If we do not have a written attorney-client agreement: I am not your lawyer; you are not my client; this is not legal advice.
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