My baby is 6m+5days old but cant fairly sit up yet. She kept leaning forward at a less than 45 degree position. Now can sit slightly more up. She has strong neck muscles and could lift up her head to turn left and right at 10 weeks old. I see other babies can at least sit upright after 5mo. Is there any issue with my baby?

http://www.parents.com/baby/development/physical/stages-of-sitting/ U can see how u would like to help ur baby practice or train her muscles towards sitting. I found the suggestions in this article not bad. My boy is 6 months today so slightly younger than yours and also not sitting yet. I am not worried as every child's progress is different and if it's of any real concern, u can bring it up to the pd. My nieces also took longer to sit and walk but all is well now and they are in primary school already, all good and active. Don't worry too much. Like suggested in the article, u can use a chair or let baby sit on u supported while she tries and explores sitting on her own. Sometimes he will practice or try sitting up when we put him in the high chair or in bed with pillows at his back and sides then we will clap and praise him - so he associates it with praises - I think u can try encouraging more and be more smiley so baby will want to keep trying