Everyone fighting Valentina gets their striking output tanked by a good 40-50% compared to usual, counting on volume to win is a losing bet. Also, Val has a black belt in TKD so she knows how Silva's kicks work since it's something she's trained since she was a kid.
Then there's defence and reads. Natalia's had a lot of success kicking so far since her opponents aren't good at reading, defending, and countering them. They always block or eat the kick and reset which allows Silva to retract her kicking leg and bounce back out of range, Valentina will often time & punch or kick her opponents at the same time they're trying to kick her which is how she dominated Fiorot in the 1st round and spinning kicked her later in the fight. This is gonna be a problem for Natalia since she usually leaves her head straight up in the air and right on the centre line when she kicks, and it's the same with most of her strikes when she's the one stepping in.