A breastfeeding mother has had an emotional encounter with two orangutans at Melbourne Zoo.

Elizabeth was at the zoo on Sunday with her family, celebrating her three-year-old daughter's birthday.

Her 13-week-old son Eli was hungry so she walked around the corner to breastfeed him in private.

That is when two orangutans came over to watch.

"I went around the corner to be a bit private and I was breastfeeding and this orangutan locked eyes with me and came over to check out what was going on," she told 774 ABC Melbourne.

"It started off with just one, then another one came over who seemed to be a bit older and shooed this one off for a little while.

"And she [the older one] came over and gave me a bit of a nod."

Elizabeth said she felt the nod was significant because she had been unable to breastfeed her first child.

"It was absolutely amazing," she said.

"I felt so proud and I felt she was proud of me and ... I don't know. It was just amazing."

Other zoo patrons saw what was going on, and a crowd gathered as the encounter continued.

"They were all just in awe of what was going on," Elizabeth said.

Elizabeth's mother took a photo which was shared on Facebook.

Her baby has red hair and Elizabeth said she thought maybe the orangutan thought she was nursing a baby orangutan.

After the encounter Elizabeth and her family joined up to be members of Melbourne Zoo.