The 50-year-old Melrose Place actress announced her engagement to long-time boyfriend Jack Wagner in August.
She told People: "Ava was so excited when we told her. She hugged Jack, said congratulations.
"And she immediately wanted to see the ring. Then she ran and Facebooked her new stepbrother."
Meanwhile, Ava - whose father is Bon Jovi's Richie Sambora - exclaimed: "I want her to do what makes her happy. That's the main point."
Locklear and Wagner, who have been dating since 2007, refuted split rumours last year.