There are so many tools or Softwares which are too useful for learning the language. As you need to learn the correct pronunciation of words while learning the language then you can use those tools to listen to the correct pronunciation.
It totally depends on you that which genre you like the most according to you interest. If you are facing some problem with literature than I would suggest you take the help of a personal tutor.
I don't understand that flash card can help you to improve your vocabulary, I would suggest you read some good books and use the dictionary to understand the correct mean of new words. I'm sure it will help you a lot.
I don't know the Russian language but one of my friends knows so I just asked him about so I can answer you that it is not so complicated language. You can learn it.
I would like to appreciate your passion of teaching to your kids in this age. Your daughter is just 3 years and you have started teaching so it's a great work done by you and it will be beneficial for your daughter.
If you are trying to learn the Chinese language then it's too good for you to watch the Chinese movies and shows. It will help you to improve your language and you will know the correct accent.
I think that you should keep trying because one day you will get success and you will find that now you are not making any mistake. Practice it more and more to get success.