Absolutely, my immediate concerns may not apply to you.
You may well have had a present and supportive partner (with whom you have remained and had your second child), combined savings, an earned income to support you/partner/child, a plan, pursued your education, got into employment, been and remained entirely self-sufficient (without requiring support from family or the state) etc.
You may have been raped and things were entirely out of your control, particularly as you follow the Catholic religion. In that instance, my god would you have my sympathy and I'd want to do whatever I could to support you/your children and share the privileges I've worked for.
The above does happen. But I'd say it's the exception not the norm (basing this on the numerous teen/young Mums I know) hence I would assume the above don't apply and wouldn't therefore be drawn to striking up a friendship with a teen Mum. As I said at the outset, though, I wouldn't treat you any differently to anyone else if you were to approach me - you just probably wouldn't be the first person I'd hone in on (not that I'd really hone in on anyone... Too busy focusing on my child and not actively on the lookout for new pals).
In response to the fact you're Catholic and, therefore, abortion is off limits, that to me suggests you should have taken extra precautions with contraception (coil, condoms, morning after pill etc) or simply avoided sex. I responded to someone else to say I think it's selfish to put one's own fun (sex) above a potential child's life.