MY ds used to poo everytime we put a clean nappy on him! It seemed like he didn't like to poo in a wet one. Are the ones you are taking off her wet? If so, you might put her in a clean Kushies for an hour before bed?
Otherwise why not try putting her on a potty before putting a tots on? I know 1 is rather early, but she obviously has bowl control. Make a game of it and explain that she's such a big girl if she is really good you'll let her sit on the potty before bed (but in a no stress way, so don't stress if she doesn't do anything), but it's worth a try for a week and see if she'll rather use the potty.
There is a group of women here in New Zealand who NEVER put their children in nappies, and the kids go on potties (or buckets!) from birth! (not that I'd try this). So even though 1 seems really little, she might just be an early starter, and other kids do do it younger.