Hello, welcome to the forum!
This is just the sort of thing we want the forum to be used for- people sharing ideas, resources and helping each other.
There are some great resources out there that may help you to think things through.
The Housing and Support Alliance is a mine of information on these kinds of issues, as they can give you independent advice on housing and support options.
Are you living in Oxfordshire?
It may be useful to contact the South Learning Disability Team in Oxon as they may know of other families in a similar situation who are looking for people to share a property together.
It may also be worth posting on the Oxfordshire Family Support Network and on the LDOX Facebook page to ask if there is anyone in a similar situation.
There are housing providers, such as Golden Lane Housing, who may be able to link families together in a similar area who are exploring options.You can log enquiries on their website.
It may also be worth contacting the Oxfordshire Association of Care Providers to know about the range of options as far as care provision is concerned.
I think the key thing is to make sure that your sister has had a recent assessment of her care needs so that you know what the likely budget will be for her support, as some families have found it difficult to get funding for their relatives when they get together with other families and this has made it difficult to go forward, unless they have eligible needs and a funding package agreed at an early stage in the process.
Oxfordshire County Council are working on a guide for families considering self -funding for housing.
If you mail email@example.com with you contact details, we can send you the draft booklet - though it is work in progress- but it does have some useful points to consider.