Congratulations. I have five failed foster dogs and have never regretted getting any of them.
My daughters started the local rescue and I foster for them. So far I have fostered 57 cats and dogs since I started about 7 years ago. I currently am fostering four cats. Three have feline Parvo and require IVs twice a day and one had a cleft palate and went through surgery last Friday.
The dogs that I've kept all have "issues" that made them near and dear to me. One was run over as a puppy and lost a leg, one has seizures, one was mistreated and had some serious trust issues, and two stayed with me almost a year and no one wanted them.
I think you made a great choice and I hope Rosie has a long and happy life.