If you wait until spring of sophomore year to use any of grandma's money, there will be zero impact on need-based financial aid, assuming the student graduates in the normal four academic years. If you can transfer the 529 account from grandma's ownership to parent ownership (not all 529 plans allow ownership transfer like this), distributions for the student will no longer count as untaxed income to the student two years after they are made, but the funds will have an immediate financial aid impact as a parent asset.