I would look them up and email them. You are under no obligation. Just tell them you are putting the feelers out. I did this when looking for home carers for my dad. Called a fair few companies to compare prices and no one minded.
Hi cleo I live in Cambridge and the going rate is somewhere between £900 and £1500 per week. It depends massively on what she needs in the way of care. I work for a care company so please feel free to message me if you want any advice.