I know that we are generally biased to think that a 15 year old girl CAN NOT take care of a baby, but there exists a small % of the population where a 15 year old girl CAN take care of a child. Heck, some women at 30 don't know better either. Age, imo, should not be the judge of one's responsibility and intelligence level.
I think that it's mainly got to do with attitude. If she has the right attitude, she can be a good mom. (I haven't seen the video, so, am just discussing in general) A lady who is 30, let's say, is no better than someone who is 15. A 15 year old can be just as intelligent as someone who is twice his/her age.
If I had a 15 year old daughter who came up to me about this, I would not automatically shut her out and tell her NO. I'd listen to her and discuss all possibilities. This is all hypothetically speaking.