I don't know if a Disney Rewards card is technically transferrable or not, but Disney Gift Cards can be sold.

I'd have her buy Disney Gift cards, or if she didn't want to do that, I would buy the rewards card from her and then buy my own gift cards.
I know you go a lot, aubriee, so no worries about the rewards card expiring before you could use it. But Disney Gift Cards never expire.
The only negative I can see is if she is trying to scam you, she could report the Rewards card lost and have the dollars on it canceled. I suppose she could do the same with gift cards, though, so it depends how well your DH knows the coworker.
Edited to add:
I was curious about transferring Rewards points, so I checked the terms and conditions:
5. The Reward Dollars accrued and posted to your Card Account monthly billing statement, and the Redemption Cards issued under the Program, are not the property of the Cardmember, and cannot be bought, sold, encumbered, transferred, assigned or extended in any manner whatsoever (including upon death, as part of a domestic relations matter or otherwise by operation of law). Any Reward Dollars accrued and/or posted to your Card Account, and any balance of Reward Dollars on your Redemption Cards, shall be permanently forfeited upon the Cardmember’s death.
I haven't ever been asked for ID when using a rewards card, so you'd probably be fine, but to be technically correct, you should probably buy Disney gift cards from her instead of rewards dollars. I think Walgreens has Disney cards that you can put any amount on.