It's really important that you can trust the professional with whom you are entrusting your child or other relative. If the independent Speech and language therapist is a member of ASLTIP, they will automatically be members of the Royal College of Speech and Language Therapists and be registered with the Health Care Professional Council. They will be fully insured and it also means that they will have access to professional supervision, which is essential for all professions.
You can use their website to search for a speech and language therapist in your area http://www.helpwithtalking.com/ You can also use the website to answer questions you might have.
You can find out if your therapist is registered with HCPC here http://www.hpc-uk.org/check/
The RCLST site has lots of info about all types of related issues including career advise http://www.rcslt.org/
Small Talk Speech and Language Therapy are members of ASLTIP, HCPC and RCSLT http://www.helpwithtalking.com/Member/Mrs-Elizabeth-Hill