Yes. IRS Notice  2008-59, Q&A 33 addresses the question of a dependent being claimed by a former spouse.   
Q-33. Do qualified medical expenses for HSA purposes include the § 213(d) medical expenses incurred by an account beneficiary’s child who is claimed as a dependent by the account beneficiary’s former spouse?
 A-33. Yes.

The IRS issued guidance on the transfer of funds from an IRA to HSA. This notice provides guidance on a qualified HSA funding distribution from an individual’s Individual Retirement Account (IRA) or Roth IRA to a Health Savings Account (HSA). The qualified HSA funding distribution is a one-time transfer from an individual’s IRA to [...]