when my mother calls my phine does not ring. She has to leave a voicemail message. i fet calls from everyone else

See the reply to:

Call goes directly to Voicemail on iPhone… - Apple Community

and:

Block phone numbers, contacts, and emails on your iPhone, iPad, or iPod touch - Apple Support

If it’s not a block...

Are you possibly sharing an Apple ID somehow?

Is there some linkage between your cellular accounts in the cell network?

Were both of these phones once yours (or once your parent’s)?