New job and no credit rating for financial associate

Hi all.

Love the forum! Hope you guys can offer some advice.....

I am looking to apply for a mortgage in the next few months. I have £50k deposit (20%), and looking to buy a £250k house. I previously owned a house, but sold it a few years back. I don't own one now.

Two potential issues I foresee. How much of a problem do you think this is, and if so, what could I do to fix, or how long do I wait to apply for a mortgage.

1) I recently went from being self employed, to a permie job. I now earn £65,000 per year. However, I am only two weeks into a 6 month probationary period. Should I wait till the probationary period is over?

2) I am financially associated to my wife, who has a new credit rating. I have a long, good credit rating, but moved abroad for a couple of years (keeping accounts open in the UK) and have now moved back to the UK with my new wife. She doesn't have any sort of credit rating (abroad or in the UK), apart from the last few months. Her experian credit score is around 750, but that is mostly because there is nothing 'bad' on it....she has never had any credit apart from a bank account we opened in the UK on arrival.

So, do you think lenders will look at her lack of credit rating and not offer me anything? Would it make any difference if I apply for a mortgage on my own, compared to a joint application?

Any help would be much appreciated!