Treatment for Spooky the kitten

Spooky is a 10 week old kitten I hoped would bring a ray of happiness to my young family. Sadly it seems that she is not 10 weeks; according to the vet more 7-8 weeks meaning when I collected her she was only around 6 weeks. Everything seemed so above board when I visited her but sadly this appears not to be the case. Spooky has not been well since we brought her home and has gastroenteritis, not sure brought on by what. The vet wants to put her on an IV drip, run bloods, faecal sample, and a course of antibiotics. This all amounts to a minimum cost of £800. I feel like both Spooky and my family have been set up to fail before we have even started. I have a 1 year old and 2year old that I am currently taking unpaid leave from work to look after and to enjoy being a mummy to. They’re absolutely in love with Spooky. My husband is a hard working man working long hours. We qualify for no financial help towards Spooky’s care but are so desperate to help give her little life a fighting chance, so far we have spent just over £100 on her veterinary care but our spare monies are depleting. The vet has said that as we stand if she doesnt improve on what means we can do to help her they want to put her to sleep. I am spending every hour nursing Spooky feeding her kitten milk and fluids to give her a fighting chance. I have done so many things to raise money for charities and did 6 years community volunteering, teaching vulnerable women English and mentoring vulnerable secondary school children...I do anything for anybody.. I just please ask that someone may now help my kitten with a small donation that would make all the difference. And thank you sincerely for  your kindness and consideration in advance.