More disappoiontment

I got a call today from my sister telling me she didn't have much time to talk and would call me today to talk more but that in June she is going to be a grandma and she has come to terms with it. My nice is 16 and a junior in high school and her boyfriend is also 16 and a junior in high school and they are going to have a baby. I knew my niece was on birth control and was just hoping that this would not happen but for some reason I am not shocked. My husband and I felt it was just a matter of time before it happend. I believe what I feel is more disappointment. I am in a little shock though at the sound of being a great aunt at 26 years old. Here I am 26 and married and still not sure if we are ready to take on the responsiblity of a baby and my niece is telling me that she is okay with it and her boyfriend and his family are excited about having a baby. Is it just me or should this not be an exciting moment. I realize that it is done and I need to support my niece but I still can't say I am happy about the siuation. I wasn't able to speak to my niece in person but was texting her and from what it sounds it was only a matter of time as she was not taking her birth control correct and they didn't use protection. I just feel for that baby and really hope they are ready to grow up and take care of him/her. I haven't spoke to my sister but from the sounds of it they are planning to keep the baby. I am trying to think of the best way to mention adoption. As much as I would love my great niece/nephew I don't feel it is in the best intrest of that baby to be raised by two 16 year olds. But seeing as my mom was 16 and dad was 18 when my oldest brother was born and my siser was 19 and married when she had my pregnant niece I don't see that being even offered. I am not sure even how to deal with this and I am trying to be supportive of my niece but I just feel so disappointed that her whole life is going to be turned upside down and not sure she even realizes it yet. She seems okay with it and I am not sure if that is a good or bad thing. Being the aunt I am not sure where my place is or what I should do? I hope to just stay low be there for my niece if needed and focus on my goals right now not sure if that is right or wrong. I plan to talk to both of my sisters and my mom today and see how that goes. If she does keep the baby I hope she takes care of herself and plan to try and be as okay and make the best of this as I can.