The Carpa by itself MUST occur before any drawing of the arc on the floor by the lady. Ladies, this is the condition that protects your back, please don't take it lightly.
If you don't have the support for your back, please, DON'T assume you are being led into a Volcada. Safely execute the good old Front Ocho to resolve the situation.
Here, the Lady can now do her embellishment by drawing that famous arc on the floor. But she doesn't have to finish it into the Cruzada, as it is not obligatory to do so.
If the lead for a Cruzada is indicated, the lady has all the time to use the Cruzada as a re-alignment tool to end up right in front of her partner.
The implication for men here is obvious. The Cruzada MUST be lead and not just assumed.