Yes it is possible to transfer enough points from one account to another when ordering an award. Marriott's T&Cs state that spouses can do this, but in practice, Marriott will allow points from any two accounts to be used.

Give MR a call, let them know what award you want to order and that you would like to pull points from another account to be able to order the award. They will fax you a form that you will need to fill out and sign. You then need to give/fax the form to the owner of the other account. They can fill out the rest of the form and fax it back to Marriott.

Once the form is received by Marriott, they will put the needed points into your account and order the award.