First; Thanks for releasing this game on Android. I was very sad when I discovered my Ipod was a version too old to run it. I have been really enjoying this game. While an Idle game, it manages to also be a game...which most Idle games really aren't. Excellent job.
One thing that has stood out to me though is that the overly simple relationship/breeding process tends to make for a rather sixist representation of the female dwellers. The only dwellers that ever run and hide are women and children, they get a permanent happiness boost while pregnant for some reason (which makes them great for rushing rooms), and there isn't too much incentive in the game to do much more than keep them constantly pregnant.
Some simple adjustments :
Happiness. Remove the permanent Happiness bonus. There is no reason for it. It seems to be there to counteract the negative penalties of being pregnant (ie always running) by making them better at Rushing rooms. But as it stands it feels like the goal of all women in Fallout is to get pregnant. six gives both participants a Happiness boost, but eliminate the 100% happy baby machine bonus.
Gestation/Maturity. Reduce Gestation time to one hour, change maturation time of children to five hours. Female Dwellers cannot get pregnant until two hours after giving birth. This leaves the amount of time it takes to produce a new worker the same as well as the overall reproductive rate in the game, but also prevents female dwellers from just being baby machines.
Cowardly Dwellers. Give 10% of all Dwellers a hidden Cowardly trait. If they are a Coward then they 100% run from any incident just like children and pregnant women. This is reduced by arming and outfitting them, just so it doesn't make them completely useless. Giving them a weapon eliminates the penalty, just giving them clothes makes it 50% likely they will run.
Extra possibilities:
Give female dwellers a hidden trait. 20% love being pregnant (Happiness bonus while pregnant), 20% hate it (Happiness penalty while pregnant), 60% are indifferent.