We stayed at the Vermont hotel a few years ago so no idea if OK now but was nice then, about £100/room/night. Right in the centre of town, really close to the shops, Quayside and other places to drink/eat.
Village hotel is out of the city centre but has a bus stop with buses every 10 mins just outside and it's only 10 mins from city centre. Fab value as you get pool, spa, pub and restaurant from around £50 per room if you're lucky.
Or what about staybridge suites? These always rate well on tripadvisor and I imagine would be lovely for a hen party. Would be within walking distance of everything as well.
Hotel wise in the city centre there is a new premier inn opening on Newcastle-Gateshead quayside soon and the malmaison is in a lovely location on the river Tyne behind the pitcher and piano and I'm pretty sure they do hen party packages.