Should i tell this girl i like her?

Just recently i started liking this one girl who is my neighbor. I am in 8th grade and she is in 7th but we both go to the same school. We hang out together a lot on weekends and this past weekend we went swimming together with a bunch of our friends. We both had an awesome time together. First off we got to see each other in our suits and then out whole group would play games that involves holding someone so we would hold each other in our arms. Then there was another game where you have to give someone a piggyback ride, so i gave her a piggyback ride and we ended up winning. I think she enjoyed because i did! Anyway we always talk together and whenever i say something funny she always smiles and laughs. I think she might like me but i can't be sure, but i like her! Should i tell her i like her or just wait awhile?