In a strange way, your wife has a number of advantages over others. It is possible to make a pregnant lady redundant, but the redundancy must not be for any reason associated with the pregnency - it is automatically unfair under the employment legislation.
In practice this means that employers have to bend over backwards to ensure that pregnant employees (who they wish to make redundant) are treated scrupulously fairly.
If she is declared part of the redundancy pool and wishes to apply for internal transfer, she should have no qualms in applying.
She has the same rights as others, and indeed some employers may be tempted to get her preferential treatment in any transfers - for fear of falling foul of the law.