The cost of life insurance varies by person based on several pricing factors that will affect the premium for your mom's life insurance plan.
Also, your mom will have to apply, to see how much it costs her, based on her health, where she lives, and the coverage amount you want.
Among the main pricing factors affecting the cost of your mom's life insurance are her age, gender, health, family health history, occupation, hobbies, height-to-weight ratio, credit history, driving record, if she smokes or not, the type and amount of life insurance, etc.
It's important to understand that you may save some money by paying an annual premium once per year, compared to paying the premiums monthly.
Also, in order to buy life insurance on your mom you will need her permission and consent. She may have to sign the application for life insurance. Also, she may have to answer some health questions, and/or take a physical exam to find out if she qualified for life insurance.
Here's how you can compare life insurance quotes online from several leading life insurance companies at once, to see how much life insurance may cost monthly for your mom.