[Watery]

This is only a pdf file (zipped since pdf attachments are not allowed) and pretty technical but hopefully some may find it interesting.
It gives a good idea of what is normal for women in their 20s as well as in middle aged women.
Even for middle aged women (whose capacity is higher), 1 litre lies over one standard deviation above the mean, so you would expect about 16% of middle aged women to be able to hold more than one litre (and lower than this percentage for women in their 20s) if a normal distribution is assumed.
Claire did about 1300ml in the clip above, which is more than 2 standard deviations above the mean (even for middle aged women), so less than 2.5% or one in forty women would beat this.