Im 13 and want pleasure without my mom finding out (females)

Ok im 13 and i don't have privacy i want to masturbate which of course i do alot in the shower but its getting really boring and i love to pillow hump but i never can with my mom always checking on me i have a door no lock and she checks on my constantly so i never get to pleasure myself!!! i get really turned on really easy and i don't know what to do i don't want to tell her i masturbate but i don't want to hurt her either i mean her son (aka My brother) past away and i don't want to make her mad by telling her i want privacy please help how can i do this without her finding out and is there any good ways without me sticking anything up there