I would wait until your wife is back in Thailand and you are divorced. Once she's there she is unlikely to make any claim on your UK assets - it would be very difficult to do so. As part of an 'easy divorce' in Thailand you will be asked to sign a certification that you have agreed on the division of assets and the custody of and access to the children.
If you haven't come to such agreement the divorce will have to take place in the courts. I doubt such a certification would be regarded as legally binding over your UK assets but I also think that your wife will be unlikely to make a claim if you have reached an agreement.
However, if she starts any action in the UK before or after you get divorced in Thailand - you'd better see a lawyer. Quite a lot of Thai girls think they are entitled to 50% because they have heard that through the Thai gossip channels. That is very rarely the case - especially as she's been in the UK for a relatively short time and I guess you owned the house before you married?
There are various things that a a UK court would take into account before deciding the split if the matter was in front of them. 50/50 is very unlikely although I am mindful that you have children.
As far as I know, any financial agreement you make upon divorce in Thailand is legally binding but only within Thailand. I doubt a Thai court has any jurisdiction over you outside the country. However, you don't actually have to register what the agreement is, you can but you can also just sign to say that you have reached agreement.
If your wife trusts you she will probably accept that you will support the kids but she might want a lump sum or some other guarantee on that. Only you can know what she is likley to want but I'd suggest you start discussing it with her now. Try do do that without discussing the house but be, as it sounds like you are, mindful of your kids.