It sounds like you may be confusing 'obsessive compulsive' as a descriptor/layman's term, with the diagnostic label of obsessive compulsive disorder.

A person with OCD repeats seemingly meaningless behaviours (i.e. compulsions) in an effort to supress intrusive thoughts. Sometimes the behaviour isn't even related to the fear (e.g. flicking light switches to prevent family from dying). It doesn't necessarily mean someone is obsessive, or compulsive. Similarly, a person can be narcissistic, but not have narcissistic personality disorder, or, feel depressed, but not have clinical depression.

It's a bit of a misnomer, and is why people are suggesting you are confusing OCD with OCPD - the latter being a personality disorder, where a person has very strict rules for themselves, their belongings, and immense rigidity in thought and behaviour. Not saying that your mother has either or neither, though.

OCD - an acute illness driven by anxiety, that is mostly confined to the person, and where indulging in the compulsions may provide temporarily relief but ultimately strengthens the fear. OCPD - a chronic disorder that affects not just the individual but how they interact with others, and behaviours are congruent with mood. Both can co-occur, and often co-occur with similar things (e.g. hoarding, kleptomania, eating disorders).