Wouldn't have Yvonne drowned in the jacuzzi?

[dream_master]

I don't really watch The Dream Child as often, but it occurred to me during tonight's viewing that Yvonne was in the jacuzzi, under water, the whole time during her dream. Shouldn't she have drowned of her own accord? Sorry if this has been discussed before on the old board before but it just doesn't make sense to me how she didn't end up drowning anyway.