Bankruptcy doesn't put a lien on property. But if your mother is still in her Chapter 13, she should discuss this with her own attorney as she may need court or trustee permission to proceed. Hope this perspective helps
Presumably, she was able to exempt her home. Were she to then gives it away, it would appear to the court that she no longer wants it, and the court could recover the discarded asset for the benefit of her creditors. This is certainly the way pre-bankruptcy gifts are perceived. She needs to consult with her chapter 13 attorney before she does anything. It might require a motion for court approval. These things are dependent upon how they are dealt with by your local court and trustees.
I agree with the answers above. The bankruptcy does not create a lien but she should consult with her attorney. Depending on the language in her chapter 13 plan the property may have vested back into her at confirmation, but in many jurisdictions the property stays apart of her bankruptcy estate, meaning she can't sell it without court permission.
This answer does not create an attorney-client relationship. The information provided in this post is not legal advice but is general information. If you have questions concerning your specific situation, you should consult with an attorney in your area