My oldest took forever to teeth. She got her bottom two at 8 months, then the top two just after a year old. Months between the different sets! She teethed until she was 2.5, seriously.

My baby already has 4 (at 9 months) and is working on a 5th. I'm blaming that for her horrendous sleep because I'm just flat out losing my mind. Bright side..maybe it'll get better when she has them all?