Well, it's a bit hard to say what your actual problem is...
- first of all, why does your version of the silvanshee have an intelligence of 17? - If that's a change to the race you wanted - then it's cool! I am only saying that a normal silvanshee would not have such a high intelligence, even as familar.
- Your familiar does not really get your witch'es skill points, it get's its own. Which would in your case be 18, so the program is right to consider these 38 points overspent.
A familiar only has the ability to use it's masters skill ranks instead of it's own, if higher. Those numbers are overlaying your actual ranks. In addition, you cannot spend more points on a skill than you have hit dice - 2 in the case of a silvanshee.
Try to give your witch - say - 1 rank in sense motive. The silvanshee does have 0 ranks by default, but the program will give you a purple 1, showing the skill of your master. Now give the familiar 2 ranks in that skill (provided it still has points to spend left!) - notice that the first rank will turn the 1 black, indicating that your familiar's and witch's skill ranks are identical. The second rank is normal. If you would want to spend a third point, it would be illegal, because the silvanshee currently only has two hit dice!
So... this was a bit complicated and confusing. I hope you can make sense of it, though.