Help unsure if I’m being cheated on

I have a question for yall. So I caught my gf cheating 6 months ago via FT and calls with another man. We worked it though and it’s been great since, well I found out she has 52 min history on FT from the iPhone battery usage in the last 24 hours but she claims she was never on FT. Does that seem weird or does iPhone have inconsistency with battery usage? Seems to me why would the iPhone magically put 52 min of FT activity unless it was unused which she denies all together:/