K.R.
Hello
I went through a very similar situation. I tried to 'sleep train' my daughter at 4 months. We tried the cry it out method and it did not work for us. I know many parents who swear by it. After about a week of hour PLUS crying each night we went back to rocking her to sleep. Around 7 months she started to put herself to sleep. She is now also most 9 months and MOST nights she puts herself to sleep BUT occasionally we need to rock her to bed. She just started putting herself to sleep for her naps. My suggestion is to go with your gut. If you do not feel right than stop it. You could always try again when she is a little older.