I've matched with a first date's friend... What are the rules?

I (26M) matched with, lets call her Sarah (24F) we went on a date and had a good time. We spoke about a second date, but that fell through as we both got mutually busy - she was entertaining family and I was away for a week. Neither one has reached out to set another date up yet.

In that time I matched with another girl (call her Jane), but after matching with her I realised Sarah is in a photo with Jane. Jane has initiated the conversation and is waiting for a reply.

Whats should I do?