Georgina Dodd, 69, of Lairg, in Sutherland, has been ordered to carry out 300 hours of unpaid community work.
She must also wear an electronic tag for the next 120 days as an alternative to a prison sentence.
Tain Sheriff Court heard that Dodd embezzled the money from Childless Overcome Through Surrogacy (COTS).
She set up the charity with her husband Michael in 1984 after their son, John, was born to a surrogate mother.
COTS offered support and services to childless couples who had to pay a membership fee and annual subscription to the charity.
Between January 2005 and October 2006, Dodd "frittered away" £50,000 her lawyer Liam Robertson told Sheriff Chris Dickson.
Mr Robertson said: "It is as simple as that. She can't explain where it went. But she accepts full and unfettered responsibility."
The court heard that Dodd set up a secret account in the charity's name and also wrote cheques to herself from the official COTS account.
She also moved funds to accounts in her son's name, but he did not know where the money had come from, the court heard.
Dodd had earlier admitted embezzling £50,000 and sentence was deferred until Monday for a background report.
Sheriff Dickson told Dodd he would not jail her because there was an alternative open to him.
He explained that it was because she was a first offender, at low risk of re-offending and she had repaid £15,000 of the money.
But he added: "I also take into account your personal circumstance and the testimonials on your behalf.
"You are the primary carer for your husband and your sister-in-law and this matter has been hanging over your head for a considerable time."
A woman whose son was the first person in the UK to be conceived through surrogacy embezzled £50,000 from a charity she set up 33 years ago.