I've been through this quite extensively with my mom and her acct. and this is how I understand it. According to the IRS, Caregivers, along with nannies and some other household workers, are a special class of workers with very specific tax regulations. I'm not going to go into the details here, but you are not legally an independent contractor although that's how it is usually handled by most caregivers/employers. It's quite expensive for the care receiver to pay these taxes as an employer (your mom). It's not legal and if your mom was audited there would be taxes due.
To me, this is a political issue about equity in the system. These are typically female positions and they are not getting tax contributions by employers to their social security and retirement. Most caregivers are paying for their own very expensive individual health insurance or don't have it at all themselves.
This money paid to you can be considered a gift rather than wages and you would not need to pay taxes. As far as consequences for gift tax on your mom's estate, my understanding from many talks with my mom's acct is, you can receive money over $13,000. BUT it's the amount OVER $13,000 for EACH person receiving a financial gift that will be pooled together and taxed in the estate upon death when the total reaches over $1,000,000. So if there's not going to be that amount pooled in the end, there won't be any gift tax owed upon death by the giver. The acct would file a gift tax return, documenting the gift amounts year by year. There is no tax to the receiver.
And yes, be sure to keep track of all medical expenses to take the tax deduction.
I strongly advise you to hire an acct and not trust what any of us non-professionals advise. It is well worth the money to have access to this person's expertise and counsel. My mom has dementia and I have developed quite a good relationship with my mom's acct which I value quite a bit during this difficult time.