Airline employees see every race, religion, etc all day long. I don’t believe what the mother is saying at all.
Post 9/11, I had multiple passengers report to me that they thought a certain passengers was acting suspiciously. I reported it to the pilots and a very thorough investigation was done - without the passenger even knowing of it or that they were being accused. Once all was good, I reassured the passengers that all was good and we were on our way.
Going up to the cockpit, closing the door and reporting what multiple people had. said, I almost collapsed and was shaking. Turns out, the guy was just a nervous flyer.
Those FAs who reported that mother could have easily seen a relationship between the mother and daughter and that the child wasn’t being trafficked. However, I do not think it was lawsuit worthy unless the mother was put in a serious situation and threatened by LE.