Hi I have a problem with my small pup, she was 4ozs at birth had to feed her myself for 36 hours from day2.now she is 6ozs, is it alright i have tried to top her up but she will not take it.She is small but healthy is there anything else i can do i am so worried about her by the way she is a cavalier king charles. Hope sameone can help me thank you all

I haven't bred CKC's but that seems small for a new born. Years ago my Yorkie pup was 4ozs from 5lb Dam.
Is she with the dam when not being fed? Why are you having to feed her?
How old is she now? If she is only a couple of days old then I would think she is gaining reasonably.
How much replacement milk are you giving her? She will only need a few mls every hour or so.
Are you making her pee/poo properly?

If she is not with the dam then you need to keep her warm, I'm sure you are.

This is all I can think for now someone else will come on with more help soon.
I haven't had a litter in years so I'm a bit rusty. I rescue ferrets and often have to bottle feed them.