Discoverd mineral rights

I am new to this so I may have a lot of questions. Recently my family was contacted by a gas/oil company. Apparently my grandmother and her husband had mineral rights in AR. The company said that we were entitled to royalties. My GM and her husband divorced but nothing turned up in divorce papers reguarding the MR. Her husband also had kids. Since her exhusband died first wouldn’t that entitle my GM to all the royalties inturn, my family getting all the rights ? The other questions I had Is how do I find out if there were more MR owned by them? and if someone else is drawing on them how do we get that stopped and corrected?

You would only be entitled to Royalties if they have a lease on the mineral rights that you have agreed to. Then you would only receive royalties if they actually drill and produce something. Regarding your MR and your grandmother. You would have to search for the mineral deed, and have an oil and gas attorney review the deed, and then run your chain of title. I am sure the o&g company has done this, but those rights may very well be split off into divided interests between your grandmothers heirs, and your grandmothers husbands heirs. Also, if someone else is collecting lease bonuses or royalties off of the MR, then most likely you do not own them at all.