you can't leave him with the silkie unfortunately. If she decides to hurt him then it will be too late and there is a high chance she would.
Raising one alone is not great but it can be done. Realize she will cry a fair bit more than if she had company so the noise will get to you. Add a mirror so she can look at herself and give her a night light like you would a little kid. It will sleep a lot on the first week and the night light will keep it calm so son't worry about giving it night time as it will just cry a lot.