I don't want to sound judgmental, but this woman somehow feels "child-like" to me. She is 24 but sounds like a teenager girl. I can't exactly point out why, but something in her words gives me this feeling.

Of course this, even if true, doesn't change the real issues her boyfriend has. But my impression is that BOTH of them somehow haven’t yet become real adults, mature and independent. And maybe that's one reason they were attracted to each other.

If this was true it would change the perspective: because instead of having one adult and one "older kid", we would have two kids (and usually two kids can hardly make a relationship work).