don't worry about the crying - she's a baby, it's expected
2.5 hours during the day is really fine. She may well be getting a bit bigger, more awake and just needing less sleep time. THere is not optimal number of hours that babies need to sleep - they're all completely different. Worrying about the hours and spending aaaages trying to get them to sleep will make you absolutely crazy. Try to just let things be if you can.