The St Annes Hotel is not in Blackpool it is in St Annes. St Annes is about 4 miles South of Blackpool Pleasure Beach. The centre of Blackpool is another mile North of the Pleasure Beach. You can see the
hotel here .
I can't recommend any holiday flats in St Annes, I can recommend some about 30 meters from the Bond hotel on Bond street. As far as I am aware the Bond hotel on bond street specifically caters for people with all levels of disability. Depending on how disabled your family member is they might be able to stay at a less specialised hotel that has disabled access??
If you need any help please let me know and I will try and assist.