Virtually all public colleges and a good number of private colleges use the financial aid methodology set up by Congress, essentially the FAFSA route--so what counts and doesn't count under FAFSA is likleyto be very important if the other assets and income are quite modest ---- at the very least Mom would be wise to include flexibility to make use of the rules.
I somewhat disagree that to use a nonparent account owner is always filled with danger---I'm sure that in many a case a 3 party is much safer than a parent who might be tempted to raid the account for any number of reasons OR not distribute as hoped to the beneficiary--now for 50K the aid impact of a 529 is something just shy of $3,000/yr---worst case 12,000 of Mom hold it stubbornly for 4 years--not fatal I'm sure but nontheless if one can save 3K+ via a safe move its a move to consider--
The new rules to go into effect for FAFSA make it count the same way whether the parent or child (UTMA) owns the account.
Given the separation of ownership and beneficiary status, I'm not sure there is any requirement that child owns the 529 once she turns 18,
I suppose some could debate the scope of what Mom as custodian for the kids funds can do ---but certainly a 529 seems prudent---and a 529 in most scenerios produces a higher net yield to a college bound student than does a naked asset held in childs name