Oh dear Write... praying for you. Hope you find a way to evacuate but if you don't there is lots of good advice here already for if you stay.
All I can add is don't forget batteries and make sure everyone has a flashlight, there will be power outages and you will want light, plus if your freezer is partly empty put water in plastic jugs or bottles - that held drinkable water or milk or soda previously - fill only about 2/3 full, water expands when it freezes - and put these in the freezer, your frozen stuff will stay cold longer when the power goes out, and you can thaw some for drinking water if you have to. [You can freeze milk too as long as the container is not too full. It will help keep the freezer cool too and being frozen it will last a little longer if power fails.]
Fill all your prescriptions. If you have any pets put them in carriers and keep them under the table or wherever you go for refuge - easier to grab them and go, if there's house damage and you must leave...
October's right, stairs are strong, also bathrooms are, for some reason.
Will continue to pray for you. Please post to us as you can. Love you. Will be with you emotionally through this. Hope you can get away. Hope Houston is spared... and the storm weakens.