I wouldn't reduce the bottle amount ... Try cup in morning as you've said then just play night-time by ear ... If she takes morning cup well then she might actually take night-time in a cup also. She can still have her usual amount of milk just in a different cup (if poss!). It depends on how strongly you feel about not wanting her to have a bottle. If you feel very strongly then try cold turkey. If you're not too fussed then continue with night-time bottle for a while.
Ok, have just given 2oz less of nighttime bottle and plan to give morning bottle in dippy cup tomorrow. I think she'll take that one fine but nighttime will be a battle, I'll reduce it again by 2oz tomorrow and so on...but she asks for milk as soon as she's out of the bath so I can't see it being easy. We went cod turkey in the dummy at 18months but obv she was less chatty then!!
My 25 month old still has her bottle before bed. It's a comfort thing - she doesn't feed to sleep and very occasionally asks for one during the day if she's upset or unwell. I have no problem with it at all. She will give it up when she's ready.
Mine had given up the bottle before they reached their first birthday.
As told to me by a dentist ... bottles/dummies should ideally be given up no later than age 2 ... because it's not just baby teeth that can be caused to stick out as a result, the jaw line/bone itself actually can start to grow in the stick out shape. Can't be fixed once it's grown that way ...
Hopefully won't get flamed for this but my DD will be 3yo nxt mth & still has a bottle at night. We brush her teeth after etc but with 1 thing & another, I haven't wanted to upset her 'routine' too much. She is currently potty training but when she's got that, the bottle & then the dummy will be tackled. I know that's not the "ideal" & people might suggest I'm babying her (on here, not in RL) but mehh... I'm trying to ensure she has comfort from 1 thing for a little longer. If I thought it was causing her serious harm or detrimental to her health long-term, I would do something about like yesterday.
So OP, go with your gut. If you don't see it as a problem, don't change it.
My 20 month old still has a morning and nighttime bottle, she sits on my lap and drinks it, she doesn't drink it in the cot to sleep, we obviously brush her teeth, she has been able to drink from different types of cups for months now, she talks for England so not affecting speech etc. But certain family members are expressing surprise she still has a morning and night bottle. For me, I'm happy to continue and be led by her, so when she's eaten really well she might sip a bit then say she's had enough, and I just thought she'd eventually just not want it most nights then we could drop it, so I haven't been worried about it. It's a big part of our bedtime routine, she's a very active toddler and it provides a crucial moment of quiet time to signal bed, so I'm loathed to wrestle it off her before she's ready.....but should I?? Is this a big deal?? My gut instinct is that as long as she's happy&I'm happy then we should ignore the well-meaning 'advice'??