Ann is a citizen of texas. she will soon file a lawsuit against bonnie, carla and dacid. "if annie wishes to sue in a federal court, will the court have subject matter jurisdiction over the case?"

Yes

Explanation:

She is a citizen of the Texas and also a citizen of united states of america.

The federal jurisdiction has subject matter on every state, it is only in some exceptions that the laws of a particular is different from the federal law, but note most cases, state laws are drawn from federal laws and federal laws over rides the state law.

But  in this case, it is lawsuit and if she wishes to sue them in a federal court she can , at times if she uses a state law she might not prevail because state laws are different from  each other, but using a federal court, she can and the federal court will have a subject matter.