Welcome 22407ht:
The links below go to search engines, where you can search for a therapist. You can search for the area where you live, where your sister lives or perhaps elsewhere. If you are paying cash, without insurance, I don't think you will have a problem. I believe meeting outside of an office environment might not be acceptable for some (or all) insurances. I inquired with my therapist about the possibility of a phone session, and she said she couldn't do it if insurance was used.
https://therapists.psychologytoday.com/https://www.findapsychologist.org/Is you twin a fraternal twin? There are a couple of recent members on this board who are working on a relationship with their twin.
We look forward to hearing more of your story, when you are ready to share.