Places within 2 hours from Houston for a small roadtrip

Hello! Next week is my 5 year anniversary with my girlfriend and I wanted to take her on a small 2-day road trip since she loves traveling. I wanted to ask for some suggestions since I don’t know much about anything outside of Houston other than the big cities like Austin or San Antonio. I’d prefer to limit the driving distance to 2 hours or less since we’ll be departing at night after work. She likes art museums, places with a lot of greenery and scenic views, flower fields, going to the beach (kind of hard with the weather we are having). Places that I have in mind: Galveston: because of all the museums. Austin: a little further away from what I would like to travel but I know she would love to visit and there is lots to do. Would appreciate some suggestions!