Advice please

Can't advise you directly but I am sure you can think through how the basic concepts apply to you:
A) Return of capital is far more important than return on capital
B) P2P is illiquid. Easy to buy, hard to sell. Treat it as though you are buying properties or things that you have to auction later. It is not a bank. So you first need to ensure you have ideally 6-12 months of liquid funds available in your portfolio of savings to cover  'opportunities and disasters'. If you lost your job/got ill/etc. 
Then you have funds for 'investment'. 
Decide on the risk you are prepared to accept and diversify accordingly.
And away you go. 
C) P2P loan selection requires time and interest to review and check your portfolio

My suggestion would be that you stick with your current allocation and continue to play and treat it as play. You will have many demands with new child/wife not working /your own career. The time and energy to nurture P2P is possibly not worth it at this stage versus playing with children, supporting partners and maximising your career prospects. If it remains an entertaining hobby for you then keep it that way. And then when you have more funds and time available and can diversify significantly you can review again.

Delete to taste. Apologies for paternalism. But time spent with the computer versus time spent with children and partners is not time you can recover thirty years later; 

Some are investing their retirement pot and others are having a punt, just for the fun of it. Both are perfectly respectable reasons for getting involved, but the former requires more experience and caution, as there aren't usually enough years left to make up for serious errors of judgement.
If it's money you can afford to lose, and you're young and wealthy, get investing. You'll learn from your mistakes and have fun along the way I hope. Spread your money widely, so perhaps not with the high minimum deposit platforms at first. As has been said before - read what contributors say about each platform. It's a bit like trip adviser (others are available) the really positive and negative biased comments usually stick out a mile, but if everybody's saying the same thing it's reasonable to trust it.
Welcome to the wonderful world of p2x!