A stranger's kindness sending positive vibes across social media.

FOX's Krystin Goodwin has the details:

Sara Heller's son Brody was born with a cleft lip and palate. The 26-year-old and her partner Chris document Brody's journey to health sharing photos on social media.

The response has been positive, but one evening, Heller was caught off guard by a cruel comment. Someone she doesn't know wrote "what's wrong with your son's face?"

While Heller says the insensitive remark stung, her faith in the kindness of others was restored. While out to dinner with friends, the server gave her a note from a random customer.

It reads: "for the beautiful baby." Inside was a check for $1,000. Heller was brought to tears. The donation came a day before Brody's first lip surgery-and helped pay for some of his medical expenses.

Heller says she is so thankful and will continue to share her son's story online.

Krystin Goodwin, FOX News.

Follow Krystin Goodwin on Twitter: @Krystingoodwin