It seems to be free in the UK so I think you are right. I don't think people should be knocking her down for doing this. People laugh when she does nothing, and now that she is, some people are still saying she won't stick to it, etc. I hope that she sticks with it. Her mum seems to go out running a lot, they could even go together.I dont think she is paid to promote the app or doing it to get pregnant (she's still with Alfie, everyone), I think she just had a moment of inspiration.
But I do hope she sticks to it, exercising would be good for her AND she will find a hobby for herself, which I don't think she has at this point.