Many thanks for your patience. The issue here is that if TUPE applies to a transfer, those employees assigned to the transferring business will move to the new employer on their existing terms and conditions. Simply put, the new employer will 'step into the shoes' of their old employer and the employees should continue working for the new employer as if nothing had changed, apart from the name of their employer.
If the new employer wants to try and change some of the incoming employees’ terms and conditions, under Regulation 4(4) of TUPE any such changes are automatically void, unless the employer can show they were in no way connected to the transfer or if they were necessary for an economic, technical or organisational reason (ETO reason) subject to employee agreement or the terms of the contract permitting the change.
Some employers may try and justify changes by arguing that they are needed due to harmonisation and therefore rely on an ETO reason. However, Government guidance and case law has restricted the application of harmonisation as a genuine reason to amend a person's terms of employment. Harmonisation will only be a valid reason if there is a change in the workforce and this must involve change in the numbers, or possibly functions, of the employees. In practice, relatively few contractual changes would involve such changes so harmonisation will rarely be used as a justifiable reason.
So if you are trying to change this entitlement because you want to bring her in line with current employees or you think it is too good of a perk, then sadly it is unlikely you would be able to justify this as a change which is allowed under TUPE. Perhaps if there was a clear financial need to remove tuis, such as drastic cost cutting required to save the business then maybe yes it can be justifiable but overall it would be difficult to change it without her consent. So you could try negotiating with her but she does not have to agree and if you force the changes through she can consider taking this further.
I'm sorry if this is not necessarily the answer you were hoping for, however I do have a duty to be honest and explain the law as it actually stands. This does mean delivering bad news from time to time. I hope you understand and would be happy to provide any further clarification if needed. If you are still satisfied with the level of service you have received I would be grateful if you could please take a second to leave a positive rating by selecting 3, 4 or 5 starts at the top of the page. Thank you