If Bashar Assad's wife being British can help to settle the conflict in Syria then it should be used. If it is only being used as another form of controlling things though then it shouldn't. Just as with anything else, it can be used for good and bad. Hopefully if it is used, they will use it for good reasons and to help stop all of the killings.
The fact that Bashar Assad's wife is British should not play a role in England's position on the Syrian Civil War. It should not matter what she is or where she is from and should not have any role in the position of the Syrian Civil War as it does not matter.
No, the fact that Bashar Assad's wife is British should not play a role in England's position on the Syrian Civil War. She cast her lot of with a power hungry dictator, so she can bloody well suffer the consequences of her actions. If she doesn't like it, she can divorce and repatriate.
The Syrian Civil War is an issue in and of itself that merits its own response and does not need to be predicated upon the citizenship of the wife of one of the main players. Assad has done enough that his wife's nationality is of little concern in the broader picture.
I do not believe the fact that Bashar Assad's wife is originally from Britain, should play a role in England's position on the Syrian Civil War. That's one person, which means decisions may be based on emotions, rather than rationale. I believe this fact should be irrelevant when considering the civil war in Syria.