Have been seeing a lady of 50 for 10 months then for last month she has been feeling miserable and moody, and has no feelings towards me or her children, but has for her dog.

Sorry need to add that we were getting on great and very in love.

I read your first question and was somewhat confused because it is a single sentence with no real information and no real question. Then when I read your reply to it, I was even more confused than before.

First you say she has no feelings towards you and then you say you're very in love.

We're going to need more information to answer this.

So perhaps she is not happy with current relationship? Some people get depressed in spring time, ( my best friend does) Perhaps there are hormone changes in her lfe now.

Only talking to her will find the issues