are you using a crate. If not it might make her feel more secure if you put her in a crate and maybe cover it too so that she has a secure den. Give her plenty of toys to snuggle up to and leave her to it. If you want to go and let her out half way through the night if she isnt settled then let her out, take her into the garden without fussing her, wait till she does a pee then settle her back in the crate and leave her again. She will soon get the hang of it.