Oreo now Penny

Back in June of 2013 I adopted a kitten named Oreo.  I took her home to my 10 year old cat Allie and renamed her Penny (Penelope Gladys when she's in trouble).  I did what was recommended for introducing a new cat into the household.  I put Penny in my spare bedroom and closed the door so Allie could get used to her smell.  Then I switched them.  Unfortunately, after the separation time was over and I opened the doors and let them run around the house Allie was not pleased.  Allie and I have been through a lot and she is my saving grace.  So I thought, what will I do if Allie continues to hiss at Penny and just hates her?  But I stuck it out.  Allie began to spiral into depression and it made me really sad.  It had been about 6 weeks and when I said, "This is it!  I can't do this to Allie.  I have to either find another home for Penny or bring her back to POA."  A friend suggested I wait another month.  I was hesitant because I didn't want Allie's health to deteriorate or resent me even more, but I did.  Then one day, Allie was laying on my ottoman and Penny jumped up next to her.  I waited for the hissing but it didn't happen.  Penny smelled Allie and Allie smelled Penny and then Allie licked Penny and turn her head and went to sleep.  I thought, "is this enough, or just an isolated incident?"  Well they continued to show each other affection.  They still fight, but it's play fighting.  I'm so happy I didn't give up on them.  I love them both so much!