You can transfer Microsoft points when in a Family Membership IceStorm from the 'parent' account to one of the child accounts in amounts of 400 I believe.
Instructions on how to do so can be found here Xbox Family Pack | Xbox LIVE Membership | Gold Family Pack - Xbox.com.
How do I share points with family members (secondary accounts)?
The primary member on the Gold Family Pack membership can give Microsoft Points to other family members (secondary members), so that they can make purchases on Xbox LIVE.
Give points to family members
- On your console, sign in to Xbox LIVE using the Family Pack primary account (the account used to sign up for the Family Pack membership).
-
Go to
My Xbox and select
Family Centre.
- Select the member that you want to give points to.
- Select Grant Allowance.
- Follow the on-screen instructions to give Microsoft Points to the secondary member. Points that you give to a secondary member cannot be reversed later.
Note If you don’t have enough points in your account, you’ll be prompted to add more points before giving points to the secondary member.