Hello and welcome to BW
I would wean that night feed right away. If cold turkey isn't working because of disturbing the whole house you can slowly wean within a week or two maximum.
night 1 give 3oz milk and take another bottle with water - only offer the water if the milk is drained
nights 2 and 3 as above
night 4 give 2oz milk, offer water if milk is drained
nights 5 and 6 same
night 7 give 1 oz milk, offer water if milk is drained
by this point you may begin to see an increase in her day time intake. Don't expect to see it after day 1, it will take a few days or a week for her to adapt to taking her calories in the day. so long as you are offering food she will not starve and nights should be tear free.
nights 8 and 9 same
night 10 don't offer but be prepared with a bottle of water if she wakes
continue a couple of nights. I would imagine she would not bother to wake or be hungry. If she does then offer water in a bottle to sooth her and the following night do a wake to sleep by slightly disturbing her about 1hr before her Night wake time to start a new sleep cycle, she should begin to sleep through.
You don't mention offering family meals. I would include her in all family meals by giving her the same as you eat (ensuring no sugar, low salt, not whole nuts, the usual guides on safety), try to offer finger food size pieces even if it means altering your cooking style a little, and having her sit at the table with you as you eat together as a family.
After the night feed is gone I would start switching the day time feeds, for instance offering lunch at 1.20 rather than a bottle, the 3.30 fruit then becomes snack time.
I wouldn't tackle everything all in one go but I would really get started and make a move on changing her habits and increase the variety of food in her diet with some focus.
What do you think?