I worked with a colleague for 16 years during which time we built up a friendship. A few years ago the work colleague met a new partner and had a baby at which point her attitude towards me changed and our friendship seemed to go downhill. The colleague came back to work from maternity leave but has now decided to leave the company we both work for and pursue a role at another organisation. She left just over a month ago and since then has not been in touch with me at all. Should i assume that our friendship is at an end and move on?