water water everywhere...

....but not enough to drink?

I'm sure there's info on this everywhere, but I just wanna know what everone else is doing..

The last two nights Hannah's woken up screaming - which is very unusual. She's slept soundly for about 2 months now.
Night before last I breastfed her back to sleep. Last night, however, I didn't want to feed her if I could help it, as I didn't want to start a habit. So I gave her some water, which she guzzled, then promptly fell back to sleep (and slept longer than she has in a LONG time).
So that indicates to me that she's not getting enough water during the day.
I've dropped a BF in the last week or two, so she's not getting as much fluid, and I feel terrible that I didn't even click that she might be dehydrated

Anyway. Long story short.
How much water do you/did you give your 7 month old?
And is there such a thing as too much?

DS drank about one full sippy cup per day, and 600ml formula, when he was 7 months old. He now drinks more water and less formula. We offer water during + after solids and many times throughout the day. He's never needed water during the night yet, but it is winter and quite cool down here.

I read somewhere that babies don't realise they're thirsty, so you have to remember to keep offering them water .

I give E some with his meals(I have to feed it to him atm... and that's it... just started this in last 3 weeks or so as doc and mw told me I didn't need to give him any extra water unless constipated..