I was told that the department would be restructuring so she needed to establish where I would ‘fit in’

I work for a law firm, which is the first thing you should know! When I was pregnant, I was told by my manager that I could come back as an administration person despite my role at that time being a manager of a department of 25 people. Needless to say I informed him I would be returning to my role!
6 months into my maternity leave, I was informed (by someone who reported into me – not by the business!) that a new person had been recruited who seemed to be responsible for the same duties I had, but this person had a different job title to my own. This role was not advertised. I queried how this would work with my role, but never received a clear answer.
When discussing my return to work, I was introduced to a new senior manager who I had not met before. In this meeting, I was subjected to interview questions such as ‘what are your strengths’. I explained I simply wanted to discuss returning to my job, and I was told that the department would be restructuring so she needed to establish where I would ‘fit in’! After various correspondence, I was informed that my role was made redundant. Subsequently, I was offered an alternative role which would involve managing a team of people located across the west side of England/Wales – from Cumbria to Cornwall! I have declined this role stating it is unsuitable to my change in circumstances as I am primary carer to my child and cannot for example, drop him at nursery then drive from my home in Bristol to Liverpool, do what I need to do and then be back at the end of the day to pick up my child! My previous role did involve national travel but this was approx 10% of my time – and so manageable with me being in the office 90% of the time.
The business is now considering a different role for me – but this would be on different terms and conditions as I declined the alternative. My new salary would be less than half of my old if I am successful. I have three weeks until the end of my years maternity so needless to say, I am at my wits end.
Thanks for listening