What now?

[Celestine]

I recently found a dog wandering along a road and took her in. Ive taken her to the vets to check for tattoos or chips but theres neither. We had decided that we would keep her but she is becoming a nuisance. We have 2 other older dogs which come in at night and sleep in the kitchen. The new dog, Stella, is obviously not house trained and pees and poos on the floor EVERY night. We take her for long walks before bedtime, she will not do any business until the minute she steps foot in the kitchen, then she does the lot! I cant leave her outside at night as she howls - she definitely got Beagle in her - and boy does she howl, so no good for the neighbours, my parents or my son trying to sleep. She has a cataract in 1 eye and the vet has said he thinks she is old. Shes obviously been bred from many times and had a hard life as she cries if she thinks she is going to be hit and wees from fright (we arent mean to her!) and is very submissive, crawling on her belly along the floor. I dont want to sound mean -  shes too much for us. We are going on holiday later this year and will have to pay for her jabs and boarding her in kennels but whats the alternative? Who is going to want to take this dog off our hands? What other alternatives are there? Is there a rescue place that would take her in? Feel a bit like we did a good turn and its come back and bitten our butts lol.

Thanks for any advice.