You asked me about training Miss Poppy to use the cat door. When she first discovered the cat door in our old house, she found it by herself and kept sneaking out even though she as teeny tiny. In this house, I only had to open the door a couple of times and show her the outside and she got the hang of it.
The good news for you is that there is you and your husband to train your Miss Poppy. I would suggest getting some duct tape and taping up the flap to begin with. Choose a morning when Miss Poppy is hungry and if one of you sits on the other side of the cat flap and shake the biscuit box or temptations bag. I would suggest that you just gently hold her and guide her head through the cat flap and she should figure the rest out. It may take a few trys and days, but I am sure your sweetie will figure it out.
Please feel free to email us at julieqATxtraDOTcoDOTNZ if we can help further
P.S Miss Barb - Chef Jellimeat was the only type of catfood that any of our cats got offered when mum was a girl. All cats ate it and gobbled it down. Now we have twenty flavours of fancy feast and other tasties in the supermarket, and all the cats are super fussy.