Reddit user sab_eth explained she had been with her husband for more than 10 years, however they'd amicably agreed to split up.
She knew it was the right time to tell her daughter, but wasn't sure how.
"I'm just here looking for advice on how to ease the destroying of her world," she wrote.
"I've talked to other children of divorce about their experiences and what their parents did to make them feel like shit/everything will be okay," the mum added.
More than 100 people replied on the thread with pieces of advice, tips from their own experiences and guidance on what to say.
We've picked out a few of comments, but view the full thread to see all the advice.
1. Don't speak badly of one another.
2. Don't expect her to take it well.
3. Let her visit the new place immediately.
4. Make sure she knows you both love her.
5. Emphasise the things that won't be changing.
6. Allow her to cry.
7. Explain exactly what's going to happen going forward.
8. Don't hype it up into a big deal.
9. Allow her to be sad for a while.
10. Emphasise that you and your husband are "friends" just not a "couple".
The mother who originally posted the request added an update after she'd spoken to her daughter.
"She took it as well as one might expect," she wrote. "Her dad and I told her how difficult of a decision it was and it wasn't made on impulse or out of anger."
"I won't go into detail, but I think we managed it well. Thanks everyone for advice, it helped.
"We're giving her space (she's currently playing Sims and singing Adele, so I think that's good?).
"The next week is going to be difficult, but I'm glad we told her sooner than we had originally planned. Thanks again."