Article: Finding Common Ground: Exploring Undergraduate Student Volunteering as a Support for Parents of Children with Autism. By Breithaupt and others. In Focus on Autism and Other Developmental Disabilities, 2017, 32(3).
In summary: Undergraduate volunteers can be a great resource for families needing a break from their children with ASD. Researchers ran a "focus-group" style discussion with groups of potential volunteers, and families who might benefit from the services of these volunteers and came to the conclusion that parents think it's a great idea, and the volunteers themselves could see some benefit in volunteering to help out such families.
There was one thing that stuck out to me. Parents were asked what they thought about "inclusion programs", which are programs where ASD kids interact with neurotypical kids. This is similar to what your local public school has been calling "mainstreaming". Interestingly, in this discussion, "...the majority of parens reported having negative experiences with inclusion programs" (p. 232) and thus weren't too excited at the prospect of such programs in the context of using an undergrad volunteer. Parents were also skeptical about programs that integrate ASD children with fewer support needs (i.e., higher functioning) with ASD children with more support needs (i.e., lower functioning) because "it lowers [the higher-functioning ASD child's] 'self-esteem if they are paired with lower functioning children.'" (p. 233)