Just make sure she signs all the pages where required. One missing signature and they may send it all back. I can go through details of who signs what but its just a matter of going through each form one by one and checking who needs to sign.
All your evidence sounds great! That seems fine for the text messages. Don't bother printing out that many sms msgs.
My package was just under 2 kg. I've seen people send more then that so don't feel they will be overwhelmed. This is your life. The more you provide I think the better

Just don't get out of hand lol It's the substance of what you send. Ongoing communication, visits, gifts, money transfers showing support etc

Good luck to you!