It is very unlikely that the Official Receiver (OR) would go after her share, but there have been one or two odd Court cases where it was decided that decisions of Divorce Courts on split of matrimonial assets did not necessarily have to be followed if one of the parties became bankrupt. However, I think (but am not certain) that the main case on this was overturned on appeal.
The above relates to cases where the Court had made (or approved) a financial settlement in divorce. Your daughter is not in this situation, unless the financial settlement in the separation was a Court approved or fixed one. If it was not (i.e. it was a voluntary agreement) then the OR might want to look at the position to see whether there was collusion to put assets beyond the reach of his creditors, or whether the settlement was unreasonably balanced towards your daughter. For example, if he had paid the deposit and all the mortgage there might be an argument that she should not have had half the equity.
This can become very complex and there is no certainty the OR would do anything but - if such a situation arises - your daughter will probably need advice from an expert Insolvency Practitioner.