Am I petty for this??

So I'm a homemaker and my clients wife thinks putting her clothes, and her grandkids clothes in the basket for me to do the laundry is ok. Now the first couple of times I didn't know any better so I figured I'll just do them. Over time I found that it was mainly her clothes that were being washed while the client in assigned to only had a few things to be washed. It can literally be done in one load. Am I wrong if I sat aside her clothes and let her know that I'm not assigned to her but her husband instead.....? I mean that is who I get paid for watching after, not her...... am I being petty??