sarah, sarah, sarah, did not all the 2nd timers tell you to not listen to a word that a health visitor says? Just get your baby weighed and nod and smile at any crap out of their mouths, it's pretty much all just their opinion. If you check, they rarely have any sort of research other than "my experience" to back up their ideas. (If you are v lucky, you'll find one who's got a bit of knowledge, but they seem few and far between).
Anyway, DD is feeding at 10pm (ish) after going to bed at 7ish, then she had been getting until 6:30ish before wanting a feed (don't worry, she's not sleeping solidly, you don't need to all hate me, she wakes about 2:30am - sometimes she just wants her dummy, sometimes she'll only sleep if I bring her in our bed and just cuddle her, but she never wants milk, just the cuddles), however the last 2 nights it's been closer to 5am she's been waking for milk, so I was thinking of trying the hungry baby milk at 10pm this week and see if that helps. We have to start our days around 6:30am anyway, as DH is up at 6 and DS at 6:30, so trying to feed in the night then having a lie in doesn't work.
If your DD is taking the milk, then she's hungry. It's that simple, if she really didn't want it, she wouldn't have it. Are you feeding in the evening still (as in, around 10pm/11pm ish)? If not, could you wake her for a feed before you go to bed and see if she gets through longer that way, but don't deny her milk - if she was 18months and still wanting milk in the night, the HV would have a point, but at not quite 5 months that's just some great big hairy bollocks she's talking.