Dd and mat pay

[kansasmum]

Dd has just returned to her job after mat leave.
I'll try to briefly summarise and see if anyone can advise:
Dd did NHS apprenticeship and got full time role in non hosp based job at the end.
After 2 years moved to hosp based NHS role.
Gets pregnant ( total shock - was told would never be able to have children) after being in new role a couple of months.
Manager and colleagues generally pretty horrible to Dd from Day 1- things improved after Dd involved HR but very up and down and Dd miserable in job.
Goes in mat leave. No one from work contacts her after her Ds is born etc, but Dd just gets on with being mum etc.
As time to return gets close Dd in tears at prospect of returning to the job, very stressed etc. Another non hosp job comes up. She speaks in confidence to HR who confirm that as long as its with an NHS employer she will not have to repay mat pay when she leaves, counts as continuous service.
So Dd applies and gets new job. Hands in her notice,manager pretty moody about it but Dd expected this and understood.

Manager says Dd will have to repay money. Dd speaks to HR who speak to new employer who confirm they are NHS employer therefore mat pay does not need to be repaid.
Today on dd's last day HR have now said that she should not have been paid Occupational Maternity pay ( OMP) as she didn't have continuous service from other job. So she will need to repay it. She has it in writing from HR that she is entitled to OMP and breaking down how she will be paid.

Dd's new employer have offered " proof" of NHS employer status but HR won't accept this and when Dd asks then what proof they require they refuse to tell her.

Dd phoned me almost hysterical saying she has NO WAY of paying back several thousand pounds. She is not earning a lot and neither does her dh. They've used up their savings while in mat leave with baby stuff etc.
So it would appear they have paid her in error which has only come to light cos she is leaving and now want the money back.
Seems totally unfair to me but wondered legally where she stood. She has served her notice and starts new job on Monday. Obviously this hanging over her will stress her out.

Sorry this is so long - thank you for reading.

[kansasmum]

I think she resigning herself to the fact that she will probably have to pay it back. But she's not giving up without a fight! She finished work yesterday and was paid today( usual monthly payroll) so now she's finished I assume they have no means of taking money from her?

[endoflevelbaddy]

Slightly different circumstances but my sister found herself in a position of needing to repay nhs employer for sick pay (whilst off due to an accident) which she received compensation for.
She simply told them it was spent / couldn't afford to repay and they haven't followed up at all since they original enquired. They could theoretically take it straight from her salary as she's still there, but they haven't.
I would agree with getting advice from union to hopefully settle things, but I would also persist with simply not being in a position to repay currently. I think they'll struggle if the mistake is due to them not checking entitlement in the first place rather than your DD not returning to work afterwards.