17 weeks and she won't sleep 6-7a noght

My daughter is seventeen weeks. She Sousa on her own, breastfeed, try to stand on her own. However, I cannot get her to sleep doc hours a night. She seems to still want to wake up every two hours or so. She is very active and gets her naps, she might sleep 2-3 hours of it is a good day. Also, forgot to mention that she might show signs that she wants to sleep that long but I am so scared that she might wake up that I take her feed her and put her back to her bed. All done in the dark even diaper change. Please help me, any suggestions??????!!!!!

Also, she does not poo on a daily basis she does maybe twice per week. Is there anything I can do to help her? Is it because she doesn't burp quick enough?