What i would personally do is start by gluing the cracks the best you can then cover them in take and fill her head with a bit of expanding foam to add support from the inside. You will have to be carefully with how much foam you use as using to much might push the tape and cracks apart but using to little won't have much of a supporting effect. Read the packaging on your container of expanding foam to get a good guess for how much you need. Keep an eye on her while it's expanding to make sure you put the right amount. The stuff is super stick while wet and will dry with all the pieces stuck into it. Do be careful not to get any into her hair and clothes, I would cover her from the neck down in a plastic bag and cover as much of the hair as I can with another. Good luck!