Yes, this was months after she played the whole my dead baby scenario with Julian in which she pulled in the Quartermaines to hide her secret (Ned, Monica and eventually Brooklynn).
I think the only reason why the show just didn't make Ned the father of the baby was because he and Olivia were not sleeping together. For months, they grown closer and were good friends, but they were not dating.However since the baby was born 5 months later, they should have had Ned and her get together and done a WTD scenario but ultimately made Leo a Q. Making him a Jerome brought nothing storywise.