Your lo does not really need that much in the way of milk as a drink now that she is over 1 year. I would probably concentrate more on getting more calorific solid food into her to prevent the nightwakings. The more milk your lo takes, the less room she will have for solids which are more important now. In the UK the recommended minimum intake for milk after 1 year is 350mls (around 12 ounces) and that is inclusive of milk on cereal, in foods, etc and also counts dairy products (or dairy substitutes) e.g. yoghurt, cheese, etc
Re: the evening feed, you could either go cold turkey with it and settle without feeds if she wakes in the night or you could decrease the amount you give by an ounce every couple of days until you are left with 1 or 2 ounces and you could then end it. Or you could gradually water down the feed you give so that eventually you only offer water. With the last 2 ideas you give your lo more of a chance to catch up on the missed ounces during the day and make it less likely for her to wake hungry in the night.
hth
Seona