Jennifer Aniston has been hailed a lifesaver by one young mom, whose daughter survived a major health scare thanks to one of the actress' public service announcements (PSAs) for St. Jude Children's Research Hospital's Giving Campaign.

Actress Marlo Thomas, who fronts the all-star campaign that raises millions for the medical center, has revealed the mother told her about how Jennifer Aniston's message helped her to get the right diagnosis for her sick daughter.

Marlo Thomas tells WENN, "Jennifer Aniston has been with us from the beginning - nine years. She does these PSAs which are wonderful. They tell the stories of children and what they've been through.

"In fact I had a mother come up to me the other day to tell me that Jennifer Aniston saved her daughter's life. The disease that Jennifer was talking about on the PSA was what this little girl had. Her mother recognized it as the same symptoms and demanded the doctor give her daughter an MRI, and in fact she did have that brain tumour.

"They're not vanity spots; they're really informative and there to give information."