Introducing New Kitten to Resident Cat?

I have a female cat named Poppy aged 4 who likes to spend most of her time outside of the house. I tried to take in a stray and found that after about 3 weeks of trying, this new cat was going to kill my Poppy! Anyways my brother, having no animals, offered to take this little stray beauty in. We then later found out that this stray was pregnant and she gave birth to five beautiful and healthy kittens. I thought with it being the stray that had an issue with my resident cat that, I could just maybe, have a kitten and hopefully my cat would take to her okay, but boy was I wrong! I've read a few posts about hissing and spatting, etc. but my cat actually hates this kitten and it's a lot more violent than growling and spitting. She full blown attacks the little one as if it were another fully grown cat! The kitten, who is never unsupervised, has had a few bad cuts and scrapes also. Will my Poppy ever learn to at least tolerate this poor kitty? My kitten really wants to approach her, but Poppy won't have any of it? I'm really scared Poppy might end up damaging this poor kitty for real or worse. Please help! I will have to rehome kitty and that's not something i want to consider, but it may be necessary.