It is not that uncommon for Google Image search to show nude photos, especially when you search for them, but also for queries you wouldn't expect it. But if you turn on SafeSearch and then search for [mommy] in Google Image search, you will get pictures of topless women who have had plastic surgery.
The issue is, your 7 year old children might innocently search Google Image search for pictures of their mommy and this is likely not what you'd expect them to see when they search for mommy in Google.
Google has known about this for at least 24-hours and there have been complaints about this for months, including one in the Google Web Search Help forums since mid-January.
Supposedly a senior engineer told a webmaster, "I have passed along your concerns to an internal mailing list for people working on and using image search."
I to have told Google about this yesterday afternoon, but the images still show up as of this morning. I didn't want to cover it but it is important, if you don't want your children to see such images when searching in Google Image search even with SafeSearch on.
Forum discussion at Google Web Search Help.
Update: Less than two hours posting this story, Google has removed these images from the search results for a query on [mommy].
Google also sent us a statement after the images were removed:
We do our best to keep the SafeSearch filter as thorough as possible, but sometimes images that aren't appropriate for a given query make it through. We're sorry if this has offended anyone, and we're actively working to improve our filters.