I just had an unplanned kit so don't think I am wanting to be harsh or anything but there are things to think of:
First of all, you will most likely make very little profit if any. You'll have to keep the babies til they are at least 8 weeks old before you can rehome them.Meanwhile, you'll have to feed them and separate the males from the females. Do you have a cage for it? If not, then you might have to figure how to keep them separate and that might involve spending for another cage.
Second of all, you say Lennie is bigger. How much bigger? I would worry about her struggling to pass the kits properly... A stuck kit would require emergency vet care and that definitely won't help her nor your finances.
Third of all, if this is her first time, it doesn't mean that she will take to them properly. She may do a horrible job, have stillborns, reject them, not have her milk come in right, etc. It's not always so enjoyable.
Fourth, it's possible she's not pregnant and just hormonal. Hormonal bunnies, especially females, can get quite aggressive. Not only would you be at risk of being bitten, so would your cat and other bunny. They can be pretty feisty as well. I have one that can deliver a nasty bite and she is quite the fighter. You wouldn't want her injuring another of your pets I am sure, plus, it wouldn't help finances again if you need to bring in an injured pet. You certainly wouldn't want to resent her for becoming aggressive either and it would be sad if it ever got to that point. On top of it all, bunnies often spray when hormonaland that is certainly no fun.
I would definitely look into having her spayed asap. If you aren't ready to have her spayed because it is a little bit more expensive, maybe you could look into having your boy neutered first so that you can work at bonding them happily.
If she is pregnant, then I wish her the best of luck and I hope the pregnancy goes smoothly. I hope you will be more careful in the future though as it's not all it is cut out to be, trust me, I've experienced it. I didn't particularly enjoy burying the stillborn and it was a really stressful time, not knowing if she would safely deliver.If you ask me, there are better ways to fund the neuter.:rose: