Ann
A little additional information would be needed to pin down the specific location of your mineral interest. It looks like there were multiple Taft-Catarina Subdivisions (at least Subdivisions A through K) that covered a widen area each side of the town of Catarina. Does the description in the lease you received show which Taft-Catarina subdivision it’s in, or give a survey name or abstract number?
The person who talked to your brother may have been talking about Denton Colony, not Denton County. An old map shows an acreage subdivision called Denton Colony located within Dimmit County, but I doesn’t appear to show anything else that would connect with the description you posted.
Here’s a link to a chain of discussion in Sept-Oct of last year in the Dimmit County section of this forum talking about leasing activity and recent drilling permits in another part of the Taft-Catarina Subdivision (it’s also referred to sometimes as Catarina-Taft but it looks like the legal name is Taft Catarina Lands Company) https://www.mineralrightsforum.com/t/lot-2-7-block-4-subdivision-a-catarina-taft-leasing-activity/59038
You probably realize a one acre undividied mineral interest in a five acre tract, or even the whole five acre interest, is pretty small, considering the drilling units for many horizontal wells can include one or more fully 640 acre sections of land. But it looks like Rosewood has recorded a lot of five acre or smaller leases starting about September, 2020. If they are investing the time to block up that many small interest that seems to indicate they are pretty motivated. In any case I think it would be a good idea if the five owners in that same lot agreed to stick together and negotiate as a group.
A $500/acre bonus does sound low for an area that appears to have considerable drilling activity going on, but I think the earlier comment that was made referring to the bonus amounts being paid in the Permian Basin doesn’t fit your situation because Dimmit County is way south of the Permian area in deep South Texas.