K.H.
I did a party at home for y daughter on her 4th birthday , I wanted to keep the cost as low as possible so hiring an entertainer was not an option , what we did was rent a kids table and chairs and then I bought some coloring crafts at a $ store for them to do when they first arrived , I then had a game set up called "pass the parcel" , you buy a small token prize (for example and eraser or pencil) and wrap it , and so on wrapping each prize in a layer of paper (you would need a prize for each kid) and then the last prize would be a bigger/better thing , they all sit in a circle and pass the parcel around and when you stop the music that person opens that layer and wins the prize.
As it is summer you could also have some outdoor games or some paddling pool/sprinkler play.
I have been to parties with entertainers , my kids went to a Mad Science party which was good , although I think 3 yr olds may have a hard time sitting and watching , it's better for older kids IMO , there are also magicians , however I am not in TX so cannot reccommend anyone in particular.
Hope this helps
