Hi Willow-bunny! First let me say it’s great you want to help out needy rabbits. I know you already have some issues with Willow and your Mom already, so I’d suggest volunteering at a shelter rather than bringing another rabbit home.
There may be some restrictions you’d face in fostering. Most likely you’d have to house a foster indoors and I’m not sure, but I think you’d have to be a certain age. Plus, I don’t think you can foster if you have an unspayed rabbit. Is Willow spayed? (Sorry, can’t remember, I thought she wasn’t…)
With shelter work, you’d be helping out many, many bunnies and getting some work experience. So the shelter could write up a report about you that may help you gaining work in the future. Plus, you’d get to spend time with lots of different breeds!
The other thing you may consider is Rabbit Agility classes. Perhaps you could look up if there are some nearby you. I already know Willow has the brains for it! Even if you can’t take her, once again, you could volunteer to help out.