Is this person avoiding me?

I recently emailed a past work experience colleague (I went to work outta state in a data team). I felt we got along well. I was truthful about my experience there to my school (they really did have me not doing the work I should have been doing and also asked me to come back and work for free when a position there was going). I was very positive about the girl. I know the school could not tell them anything (privacy), although I did say I felt abused there (which had nothing to do really with this girl). I asked the manager there to be my referee (he said ok) and than declined when my job rang (too busy and important apparently). I since saw the girl on the street and we had a great convo and talked for a while. I am worried since it has been about almost a year since then and I have messaged and not received a response at all! it has been nearly two months my paranoia is getting to me! I mean even if I did not like someone I would email them back I guess, is there another reason, am I being paranoid?