My 9 month old DD has been a poor sleeper since around 5 months and needs to be rocked to sleep several times a night. I'm starting to struggle with this as the night wakings are becoming more and more frequent so I want to try and get her to self settle. However if I put her down awake she will just persistently stand up in her cot and get angry with me when I try to lie her down. How am I best off tackling this issue?