Thanks for the grobag site Taurean We tried her in it last night, wearing a singlet and long bodysuit/onesie. We also turned up the temp on the heater a bit. She seemed to like it, and I loved it - she kicks around so much, even if she's wrapped she can wriggle enough to shift the blankets around. So it was great that nothing was going to cover her face. She did still get a little cool though, so I did wind up putting a thin blanket over her. So now I reckon I'll get her a proper winter one, 2.5 TOG. She's got loads of growing room in this one, so hopefully it'll still fit when the weather warms up a little.

Thanks heaps for everyone's advice