Help With Property Dispute With Deceased Member

Hello all, I’m seeking advice regarding a property ownership dispute in Texas. Here's the situation:

• The Agreement: My mother and her brother (my uncle) had a verbal agreement that if she took over the home’s financial responsibilities (mortgage and taxes), the home would be hers once fully paid off.
• Proof of Payments: My mother has evidence that she paid the original homeowner via promissory note and tax receipts. She also has an affidavit from the estate attorney of the original seller confirming that my uncle never made payments beyond the first few. The note is signed by the original owner and my uncle and my uncle gave her this note when he made the agreement with her.
• Investments: My mother has lived in the home since the 1990s and invested over $60,000 in renovations (plumbing, remodeling, etc.).
• Lien Issue: A tax lien was placed on the property after my uncle misused funds she gave him to pay taxes. She is still paying off this lien. My mother has documents issued to my uncle given to her by him.
• Uncle’s Death: My uncle passed away before the home was fully paid off. My cousins (his children) waited for her to finish paying off the property before claiming ownership.
• Legal Evidence: My mother has notarized affidavits from my uncle’s friends who confirm he intended to transfer ownership to her. One of my sisters is also listed as "POD" on a tax receipt for the property.
• Legal Challenges: A prior motion for summary judgment was denied under Texas's "Dead Man’s Rule." Lawyer we recently met with (previous attorney is seeking to withdraw citing downsizing) seems dismissive of promissory estoppel, part performance, or unjust enrichment arguments.

Does my mother have a chance at retaining the property? What should our next steps be? Any advice or guidance from someone familiar with Texas property law would be greatly appreciated.