I guess it's what ever you feel comfortable with. Keep in mind you'll probably need to express while you are out as you'll feel very full, especially her being so young.

I haven't had a 'big' night out since before kids, just can't do in case something happened and they needed me. I only have one or two drinks with dinner now occasionally and I waited both times until they were around 10 months old and were going a bit longer between feeds, particularly when they started to stretch out their bedtime/10pm-midnight feed so I had a bigger gap there.

Go with your instincts either way I hope you have a nice night out