Well, whether happy or not, I know quite a bit about this kind of experience.
Furbies are very, very moody. I am not sure which generations are which but the Furby 2012's and the Furby Boom 2013's are very moody. I know that if I leave my furby alone for three minutes it will always complain that it is hungry even though I feed it its maximum amount, so if you are not constantly right near it it'll whine for attention. Perhaps the woman did not know she had failed to check the hidden personality... just when they are about to change into a noticeably different personality, they will get a hidden personality which many people don't seem to know about... they will say things like "finally"and "aw come on" and "quit it"... so you know they're about to change. Furby booms say "come on" and "quit it", furbies just act moody and say "finally".
Even if they don't change, they'll say "finally" when you feed them or if in crazy personality, if you pull the tail sometimes. Either way, I am sure Furby is happy now. And they do cry a lot, too. They're just... furbies!