The $8901 from the 1099-Q/529 plan is unearned income and will trigger form 8615, whether she is your dependent or not (if she was a fulltime student for 5 months, and it appears she was).
Is she qualifies as your dependent, her standard deduction is limited to her earned income ($7800) + $350. A dependent doesn't get the full $12,550.
Whether she is your dependent or not appears to hinge on the support test. The $14,900 in SSDI is considered her own suooprt. Money she put into savings (including the ABLE) does not count as support she spent on herself. Scholarships are excluded from the support calculation.
The support value of the home, provided by the parent, is the fair market rental value of the home plus utilities & other expenses divided by the number of occupants.
The IRS has a worksheet that can be used to help with the support calculation. See: http://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf
