Hi Lola
You've been given some good advice here.
When you are taming your bird, keep in mind that it will be a REALLY slow process and you have to look for the tiniest steps forward and celebrate them as progress. As you have said, she is still scared of people. She can improve and it will take time. For example, my birds are quite tame for me (they'll come to me, etc.) but they've been really scared of a friend of mine who comes to our house every two weeks. So, for months now, she has been offering them a bit of peanut each time she comes by and they have never taken it from her. Each time, she'd wait a bit and then leave it in their coop cup and they'd eat it later. For the first time last week, they finally did it. Given she only sees them every two weeks, it took quite a while but she eventually won them over with her patience and kindness.
When you are offering your bird a treat, offer it on the other side of the cage from where she is. Make her come to you... don't shove it in her face as this may encourage an aggressive response such as a lunge. This was a mistake I'd make with Janey in the early days. If she was full, she'd lunge at me. You can also try looking away when you offer the treat.
When I say look for the tiniest steps forward, if she takes one step towards you or looks like she is thinking about taking a step towards you, take that as encouragement and be proud of her and yourself for her efforts.
Regarding toys, it is my belief that all birds will play with toys, you just have to find the right toys to suit your bird and this is only done through trial and error (in this way they are similar to children) ... and their interest in toys will change, what might be of no interest to them this week might be their fav toy next week. If you go to this web page, there is a list of 11 types of toys
http://lafebercares.com/what-to-chew-today/
The good thing about bird toys is that you can make them for very little cost, you just have to be careful you don't give them anything toxic. There are threads on this forum that can give you ideas on this. My guys fav toys are foraging toys and small bits of wood they can chew up.
I am a general believer in having a companion for your bird so that they have someone to hang out with when there is noone home and so that they know they are a bird. However, this will not solve your problem of tameness, in fact it will most likely make it worse. I think you need to get your bird to a level of tameness you are happy with before getting her a companion.
You can find more information on taming a wild bird in this thread:
http://www.indianringneck.com/forum/vie ... =7&t=15111
For me, introducing foraging definitely decreased lunging behaviours. You can find more information on lunging here:
http://www.indianringneck.com/forum/vie ... 01&p=69400
http://www.indianringneck.com/forum/vie ... =4&t=13466
http://www.parrotenrichment.com/ - this site has some free ebooks to download
Also, I'd be really surprised if your IRN isn't scared of your Macaw. I know you said your IRN likes the macaw but I have a feeling if they were in the same room or the Macaw was standing on your IRNs cage, it would be really scared.
Out of interest, what are you feeding your bird and how much are you food are you giving her?
Best wishes with your IRN.
Take care.
Ellie.