Yes it is her fault for lying to Sarada about Sasuke. As a mother she should've told her child everything she wanted to know especially when Sarada wanted to know about her father.
The one thing I can excuse Sakura for is the fact when she didn't mention where Sasuke was because it was classified as a top secrect mission. Seeing that she respects Sasuke's decision I can see why she never told Sarada but the fact she couldn't remember if Sasuke had glasses.
Haha some cringeworthy shit I enjoyed.
Sakura had no excuse for telling her about Sasuke's appearance and her previous memories with him. She did have good memories of him read the manga and the child does need to know of all the sad events that occured in the family. Yes she is to blame. Now read the manga and get over it.