It is much more tedious to "reverse engineer" to a suitable motherboard that will work for existing components that are on hand. I.e., GPU, CPU, RAM, etc.
Integrated graphics?
I
randomly selected an Asus Motherboard. Here is a link to the User Manual:
https://dlcdnets.asus.com/pub/ASUS/...6575_ROG_MAXIMUS_XII_HERO_WI-FI_UM_V2_WEB.pdf
Scan the manual overall but start by looking at physically numbered Page vii.
Obviously lots of information with bold print caveats and referral links to Asus's QVL.
The first factor is the motherboard form factor so that will provide some filtering down of mother board options.
Next - budget? How much do you have or want to spend for a new motherboard? Doubt that you need a high end gaming/working motherboard for your Mother. (However that is only a premise.... No offense intended.)
What you do next is get the specs for each component you wish to re-use and simply go through the candidate motherboard specifications summaries and literally check and verify that your re-used components will work on any given motherboard. Details matter.
You then need to read through the manual and envision the build you have in mind. Look for and think about any other components/parts that may be needed.
Look at Page 1-4 for example: that is just for the CPU. Likewise for Memory/RAM beginning on Page 1-5.
The system panel header (power, reset, etc.) is covered on Page 1-21. You must ensure that the new motherboard, etc. can be properly shut down. Not via the PSU switch.
People who do builds every day (Full disclosure: I am not one of them) likely know via experience what generally works with what. Even then manufacturer's change specs, support is dropped, standards evolve. And former compatibilities are moot.
My suggestion is that you update your post with the make, model, and detailed specs of all the components you wish to use.
Primarily with only a new Motherboard and CPU as I understand your previous post.
Hopefully someone can look at that list of your components and immediately know (with some reasonable degree of certainty) that all will work on Motherboard X.
Or make other suggestions such as to not reuse some given component for what ever reason(s) is/are applicable.