I'm thinking theft first, and Al-Q organized terrorism a very distant second.
Hospitals are full of things that can be sold for lots of money once stolen.
As for the terrorism angle:
* Al-Q is usually pretty wise in terms of target selection. Heavily damaging 1 hospital in Seattle isn't going to get them world stopping media coverage or damage the U.S. to the extent that it's worth losing an active cell over.
* Hospitals are a very poor choice for a bio/chem attack. Lots of medical personnel right there, hospitals have more sophisticated/controllable ventilation than your average office building.
* Hospitals are a poor choice for any attack - generally alert security on-site, almost instant comms with all possible responding security agencies, good surveillance on-site.
* Al-Q teaches very cautious target recon - an example of this might still be found by looking at the (sanitized) Al-Q training manual pages the DOJ has on the web. The (sanitized) version still has a couple of pages specifically dealing with target recon and keeping a low profile. Sending 2 women into a hospital for 'blueprints' when the same blueprints could most likely be accquired from a less secure location, possibly thru bribery - not characteristic of Al-Q trained domestic operators.
* Culturally, Al-Q leadership is predominantly Arab. First tier cells have almost no history of using females for anything operational (target recon is operational, running the books for a fund raising operation isn't) due to Arab attitudes towards women vs. men and responsibility, etc.
My bet is an attempt to find how to gain access to prescription drugs with a high resale value. Some might say that this is an attempt to generate funds for Al-Q but their fund raising is usually way more sophisticated with a much better 'risk vs. reward' ratio.
My $.02.
Mike/wulfie