My 16 year old is pregnant by her 15 year old boyfriend

Although it is illegal to have a sexual relationship under 16 years, in practice if the two people involved are close in age, and have clearly both consented, it is unlikely that any action would be taken. Usually legal action is only taken if one of the couple is a lot older than the other, or if the younger person has been coerced or manipulated into a sexual relationship. I hope this helps.