Hi i have a #2 sibling potty training question!

My oldest was very easy to potty train she was trained day and night by 2 1/2. Now my 18 month old is showing very definate signs of wanting to go potty and I've got her a potty and her own "big girl" panties. She has yet to go in the potty and I was just wondering if the 2nd time around was harder? With a little one younger than her I'm a little concerned that it might take a while. I hope someone has advice for me!

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