Why would she reply 3 months later?

So I stopped talking with a girl properly in January, Then we had a small conversation at the end of April then she basically ghosted me until recently where she replied to a message I had sent at the start of May...

When I asked her about it, She just said "lol sry about that" then we talked for a bit then said not to tell anyone from her old work because she had a reason that she couldnt tell me...

Why would she reply 3 months later?
Post Opinion