Social aniety with my 18 year old daughter

Does anyone else have a daughter who suffers from social anxiety. My daughter is 18 and really struggles talking to people which has resulted in her having no friends. She really cant start conversations and really struggles to join in. All she wants is to be able to have friendships and is really lonely. Ive tried getting her to go to groups and shes scared stiff. She's fine at home as long as its just me and her dad and is really witty with us but as soon as someone else comes in, even members of the family she just clams up and really struggles.
Just wondered if there was anyone else having similar problems please