I”m going to be controversial here but – if you aren’t adopting just yet, is it worth taking the higher paid job right now? You may not always have that option, but I suspect you will always be able to retrain as a teacher, if and when the timing is right. It is valid to want to earn some money so have have financial security, especially as a single parent. I am lucky that my ex is on a higher salary than I am, and that security for our child is priceless.
Having an extra year or two of a better paid career behind you will allow you to be less stressed generally/have some savings behind you/ allow you to take up to a year off work when you first adopt to spend some time together then? You may not have the option to go back to the better paid option.
Throughout my life I have been broke and I’ve had money. My parents both worked full time and i never felt cheated that I didn’t get enough time with them. Its more about what you do with the time you do have.