Will it cost a lot to add a driver to my insurance?

You will have to ask your insurance company. How would anyone else know?

First, if I understand correctly and if Mom will be the principal driver then the rate will be based on her....Not you. Your company may not even insure the car that way, since presumably, Mom has no insurable interest in your car.
You MUST speak with your agent about this.

Have you considered to just leave things as they are? Mom will still be insured driving the Escape if she just drives it "Occasionally". And you will still be insured driving the Honda.... "Occasionally". Wink, wink.

if you are only paying $ 88 per month for FULL coverage ( unless you purchased the Ford w/cash ), then you are getting a bargain

actually I don't know

Yes. As 23 year olds are much more likely to get into an accident.

Your insurance premiums are already too high. Please check out other insurers. My husband and I have 2 insured cars for $800/year.

Not much.

You should have added your mom when you first took the policy out. Having an older experienced driver with a good rcord is a good way to REDUCE your insurance.

Ask Geico, dummy. Unlike any answer you get in here, their answer won't be a completely blind guess.

In this case, maybe not. Your rate might even go down. Having no drivers 25 or older can drive up the price of insurance a lot. If you are the only driver right now, then you are paying a very high rare, because you are 23. Adding a driver who is 25 or older could lower the rate.

"Due to finance problems my mom agreed to take over my car loan".

Did you and your mom receive approval from your lender to do so? If not, you don't have the legally authority to make such a change. You, and only you, have a legally binding contract and responsibility with your lender. Not your mom, nor anyone else, can simply take over payments without the lender's authorized approval to do so.