But when she swapped back Vala's body was doing stuff with the stones machine and the other resistance people. So she wasn't in bed flaked out.
I believe she was sitting at the table where the terminal was set up. So for all we know, the entire time Vala was inside Daniel's body, her own body was likely slumped over a chair. We certainly had no indication Daniel was actually in her body.
Although it is interesting to note, this episode is the only time in any Stargate series when the communication stones swap genders. Really surprised they never did that on SGU.