Everyone has a different level of what they think is appropriate for their spouse to be away I think... some couples seems to spend a lot of time out and away from each other, others seem to never be seen apart.
BTW comparing another relationship is the sure fire way of putting her on the defensive and not getting anywhere fast 
You guys need to figure out what works for you.
It could be the drinking, or it could be something else that's not quite working out that she's resenting and this is just the visible thing. Maybe she feels she's doing too much with the kids or around the house and resents you getting free time while she feels that there's stuff not done?
It could also be the lack of time for just the two of you, I don't know how old your kid is but that's a difficult transition for some couples, especially at some stages. So much time goes into "family" that not enough goes into time for just the two of you, so what time you do spend for yourself is resented.
Have you offered to let her have a night or two out while you take care of the young? Though be careful with that one, if it is that she feels a lack of closeness or a lack of time together, suggesting that would make it worse.
Kind of personal, but how long have you guys been married?
My wife and I have gone through stages of this off and on, but a lot more in the first 5 years.. Her expectations and mine were different, and it takes time to find the balance that works for everyone. It's about compromise so maybe for a while you have to limit it to 1 night a week and work on whatever the root of the bad feelings is, but she has to recognize that time apart for friends is healthy too (as long as it's not escaping), and not guilt you for it.
Make sure and figure it out early, resentment can build fast.