Need help - Inherited Mineral Lease Texas

My mother’s grandfather purchased land in Atascosa County Texas. At one point, my mother (who has 4 siblings) paid the property taxes and then realized she was not the legal owner and stopped paying them. We have recently been contacted by landmen to lease the mineral rights. What happens now? Do we sign the mineral lease? Do we pay the property taxes? How do we get the property into our name? There are lots of relatives who also received the mineral lease. If the property is sold by the county, do the mineral rights go with it? Thanks for your help.

Where is your property located?

We have 20 acres in Atascosa County, TX. SS Farm Tract 5223. We have been contacted by Dora Cersonsky of Alliance Land Services. They are offering $1,000 per acre bonus and 1/4 royalty. I’ve done a little research and it appears in Texas, if the property is sold at foreclosure, the mineral rights go with it. There’s about $20,000 in unpaid taxes. I have contacted an attorney, but he’s not an oil/gas attorney. I am in the Dallas area. Any recommendations would be appreciated.