In RV Park looking to NE across Main St, coming from NW

I walked out of RV turned towards N to sit on patio. Lots of white clouds all at a certain level with lots of blue between and all under. I see a white-as-the clouds, square.. possibly the slightest rectangle, top to bottom, mostly square. It was atop.. the center square of 3 below it. At first I thought lost sign or banner off a plane.. realized no words or colors on it and moving as if one piece yet I could see blue sky below top and in between. I ran in to get hand scope and before I could locate and focus in, it was gone. Moved fast to NE and crossed where I see IAH planes taking off nearby and gaining altitude. Definitely crossed take off space and Air Traffic Control at IAH and other planes must of had a better view. Should have stopped take offs, don't see landings coming that way... or they have a better explanation. My boyfriend told me when he got back from haircut, people were talking about all the military aircraft in the area. I saw none and maybe they were staying out of IAH airspace as it was long gone to NE. I reported to Baytown PD. He said no other reports at that time. I am a retired Police, Fire, Medical Dispatcher. Ex-EMT. 63yrs old,, female. I have seen other strange things in the sky. Reported before and will again.