I think my friend is being dumb

My friend whom I love has two kid. A little girl with one man and a little boy with another in between these two she did have a miscarriage with another man. She is now with a new guy and he is a really nice guy.
His family is awesome and he is really nice to her kids, but they are trying to have another baby together.
I love her but I think this is a bad decision as they're not married and she is not financially stable to care for the two kids she has on her own. I am worried about her being a single mother of three kids. Am I wrong to be feeling this way? I want to talk to her about how I feel but I don't want her to get angry with me. I just feel like she is making a bad decision.