I hope you cn get that fixed easy! In wondering how the brackets could break, I’m thinking a past owner who drove a rough road for a very long time, had put on extra stiff shocks and kept them maintained that way, and that exceded the engineered strength of the bracket. With constant flexing for a long time ...... Just a considered guess. I agree with Kevin, the heat of welding in place on the bracket wouldn’t heat up the frame enough to make stress spots. Might be easier to do on the bench, though. Re- riveting the bracket to the frame would be a fun job! Take an old sledge hammer head(annealed)drill or machine a recess on the face that fits the rivet head nicely, and use this for a buck. Have the truck’s owner hold this while you peen the other end nice and tight. Get the rivet fairly red hot first. At least the little end. Or, you could switch ends with the owner, so she won’t feel like you are undervaluing her skills. Got to keep peace in the marriage! Might pay off.
