Job share rights?

[plfrench]

Evening all,

My wife has just been through a restructure at work and ended up taking a job share.

In correspondence about the new role, it has become apparent that if either party of the job-share should decide to leave (or is sacked), then the other one may be replaced too by a full time role. This seems a bit odd, and offering no job security at all. Surely if one leaves, then the job they are recruiting for should be for job-share hours?

Does this seem right?

[Jasandjules]

Why did she take a job share? i.e. what are the circumstances.

[plfrench]

Redundancy of her previous role. The work she'll be doing is essentially the same as her previous role, she has just ended up with fewer hours.