Can my retired mum be my guarantor?

I have got a little bungalow I am trying to rent, have everything sorted except the guarantor. My mum is a retired senior nurse, although she is only 51, and had to retire early due to ill health. She owns 2 properties, one in the UK and one in France. Also my 15 year old brother still lives at home, so she gets whatever benefit she is entitled to for him, i.e Child benefit and Child tax credit (as far as I know she has only ever received minimum tax credits payments as her earnings have always been high). And she is married to a man who also has an NHS pension and his own successful business. I have no idea of their actual income as they don't discuss it with me, but they are not badly off by any means. Would my mum on her own be accepted as my guarantor?