18months potty training

I’m not overly sure my little ones completely ready… she sits in the potty knows wee needs to go but has yet to do that part. She can name wee and poo knows a difference. Has recently been taking her nappy off after a wee and poo. She pulls the pull ups up and down. How do I progress her or just leave it as it is..? I don’t wanna miss the opportunity but don’t want her to feel pressure of it. She’s just became a big sister so lots of change for her already.