I have ordered twice from her and she is lovely. Both times I have been lucky and contacted her to ask if she has any custom slots and she has fitted me in - although it is quite a wait by the time you get to the top of the list and then with the time to ship. She very rarely has instock nappies. I would just drop her an email and ask. You need to know what you want though so have a good browse of the site.
I'm on the PBPD newsletter mailing list. So when custom slots are available, I get an email saying so. I just emailed Jen back and said I wanted a slot, how many nappies I wanted and whether I wanted embroideries or not.