Hi it’s a bit of a juggling act when they don’t do long naps as shorter time between feeds often runs the risk of snacking, which increases the risk of short naps but trying to feed at 3 hours can result in feeding right before a nap and feeding to sleep and that’s another complication.
Also at 3.5months they can often be moving towards 4 hours so 2.5 hours would definitely be snacking.
Have you tried resettling after a 45 min nap, I know for me taking my youngest on a walk in the stroller or in a carrieroften extended the sleep so the feed could be later. I also got one long nap from him in the middle of the day (matched his brothers nap so sometimes it did become catnap feed catnap catnap feed long nap kind of patterns.
I think overall it’s how it impacts night sleep that I felt was most important, if feeding at 2.5 hours has her waking lots at night, then I’d risk feeding before a nap to stretch it out, but if night sleep is going well, I’d go with whatever works.