One thing that strikes me is that you say "Now that she has finished college I asked her to help clean the house". Surely she should have had chores to do since she was big enough to help out? I remember doing household tasks (usually something like washing up, wiping up, dusting, cleaning the bath and basin etc) from the time I was at primary school - there were badges for it in the Brownies when I was about 7!
The word 'NO' comes to mind here. Ok, she's an adult and left school so you can't control what she does outside the house but you can expect her to cover her expenses and do her share of the work at home. She's had an easy ride so far and it's time for her to realise you're not an endless supply of cash. £30 sounds very cheap - you can't even feed her for that - perhaps sending her to do the food shopping would open her eyes?