As you can see, most of us are in total agreement. Yes, a 7 month old bull can settle females. Likely - no - but most definately probable.
I would wait & see if she keeps cycling. I have the same thing happen each year - I'll have young heifers start cycling while the bull calves are still with them. Never had one settle, but always a concern & always write down their standing dates & make sure they continue cycling - if not, I would definately hit them with Lutalyse. Of course, if you don't see your cattle often enough to feel confortable as to whether she will re-cycle, lutalyse is a cheap insurance.