Mom is often incontinent through the night. How often should she bathe?

I'm worried about my mum in law. She in a care home. She has dementia. She also has celulitus and is often incontinent through the night. Although her skin is unbroken at the moment she is constantly itching and im concerned she only getting a bath or shower once a week and just a wash down on all other days. Im shocked. As I bathed her daily when cared for her as ment could really keep an eye on her skin and could apply moisturiser all over and deoderant. As prior to that she was really unkempt and had forgotton to bathe for quite some time...home say that daily shower not good for her skin. Id say at least her skin would be clean....