
I found after stacking the surface assault missions (ones which don't appear in the list to hand in) makes it faster as your charity mission and the repeat mission are on the screen without having to scroll down. Also i got the 15k+ mission faster at the star-port above the planetary base in the guide. If you are having no luck and get say a 10k mission just take that and keep looking for the 15+k and if it doesn't show after say 20 minutes just spend a half hour spamming the 10k one.
Your lucky having loved ones who play! I cant get the missus to play, got her an account and everything, got pc's side by side but her account is just my trade beacon account now, hopefully they will put cute micropiglets and fairys in the game somehow so she will be interested and will play with me xD
Edit : Oh also don't abandon failed missions, they count for filling the quota so once your at 99 your good for using the technique without building your missions again until you reach king, and if you mess up and forget to click your refresh mission before handing in the charity mission if you log out and back in it will re appear saving you from spamming relogs and waiting for a new 15k one for half an hour.