How can I get my cat to stop doing this...?

She is a cat and by the sounds she is still in the kitten stage. Different breeds of cats grow up at different ages. You wouldn't want to have a Chausie that is for sure. They don't just tip things over they throw them and toss them. They do not become adults until they are between 2 and 3 in human years. The Savannah is at least 3 before it is an adult. If she likes to push things over its just a part of her character and play mode. I suggest you give her 2 to 3 play periods with you daily where you have a lot of poles that have toys on the end for her to chase. You do not decide when she quits the play. Let her decide when she is pooped out too much to play anymore. She has bottled up energy and needs an avenue to express it and most likely is still a kitten or teenager and not fully grown up. Also each breed has their own sleeping modes. Some breeds sleep all day like the Snowshoe Cat which I also have one of. And others like the Savannah and Chausie I have race and tear around the house most of the daylight hours but sleep at night. All cats are different and unique. Go with her flow and work with her. Baby proof your home if you don't want her in things or restrict her from that room. My cats are not allowed in my kitchen when I am cooking and they are not allowed in any bedrooms. Actually they have their own bedroom.... a 9 x 12 room with everything a cat could desire or need... but they still like my stuff. So the valuables are in places that they can't get to... china cabinets, etc. Let them be themselves and you will have a happier cat and home. Just treat them like you would a toddler and keep things that they can get to in a safer place.