I am flying solo with my kid (7 and 9) to Paris early December on Malaysian Airlines. We stop in KL for a little bit and they were rated highly on the reviews for family friendly airlines. It was cheaper (by 400 each) to fly into Paris rather than London, as Heathrow add big taxes. We will spend 10 days in France doing lots of day trips to before going on the Eurostar to London on the 26th of December. Just be careful when booking the Eurostar as I accidentally booked the wrong date and then when I phoned them 10 minutes later I was NOT allowed to change it and had to rebook and pay again. I have bought about $1600 euro and $2000 GBP and I have a card I am loading some cash on. I have family in the NE of England but we have organised an apartment in each city on Air BNB.