Alex Kingston was apparently absolutely shocked and thought it incredibly clever when she was told who River was, which is a good sign towards her not being Amy's daughter - because that would be stupid and predicatble. If she's Amy's daughter, they had better have another secret that's odd and out of nowhere, like that she killed Kennedy and that's why shes in the 60s.
Also: Big Finish Month sales are on in less than four hours! Hoping for Releases 51-75, and I'm sure Friar'd be pretty happy too if that happened, even if it doesn't include a subscription in the sale. (protip just in case: Avoid 75. The McGann 'Scaredy Cat'. Considered the worst Big Finish period, it's only 75 minutes long and incredibly boring and predicatble and stupid.)
Doctor pooh shirt is up at www.qwertee.com