Weaning bottle

My daughter is almost 14 months. Her doctor suggested we start weaning the bottle which we were ok with because this is the age we took both of our sons bottles. They took to the sippy cup just fine. My daughter will take a sippy cup just fine during the day. She might cry 5 minutes at naptime for a bottle then she is fine. Bedtime is a whole different story. She will cry for a half hour and refuse the sippy cup. It has been 4 days since we took the bottle. Is it normal for her to still cry at night for the bottle and at naptime sometimes? Will the crying eventually stop and she take the sippy cup without an issue? I got worried when everyone else said their kid only cried for 2-3 days after taking the bottle. Please any advice or reassurance is greatly appreciated.