Universal Credit- when and how?

[SpiderinaWingMirror]

Hoping someone can give me a few pointers re Universal Credit. Dd is returning to work 1st March. Having run circs thru calculator, income, rent, nursery fees etc it shows 130 pw. In Feb she is being paid her outstanding hols at full time. She starts pt hours, that the calculation is based on immediately after. My question
When should she start her claim? On the 1st March with her project ed figures?
Also, her dps earning change each month depending on overtime, by about £50/£100. Is thar picked up by real time payroll or do they need to update each month?

She should claim a few days after her holiday pay has been paid, she needs to make absolutely sure those wages have been reported to HMRC before she starts the UC claim. Her partners wages should automatically be reported by his employer unless he is self employed.

Thank you so much @Babyroobs. That makes sense.