Hi'ya Jodi. Welcome to TGH. Also from California. It sounds like you gave your queen palms a very nice start in their new home. Queen palms are relatively slow
growing for palms although there are some much slower. I would look for about a foot a year growth. The miracle grow will not hurt them at all. There is food available formulated just for palms that you can look into.
The biggest problem with queen palms in my area is the winds. It helps to have Some good sturdy posts to stabilize them, especially when they are young and newly planted. But I've seen even larger older ones fall over in the winds. They are not as stable on their root system as our regular washingtonias (the palms lining a lot of our streets)