No puppy should be left alone all day. When your Maltese is older, you can consider it since they are one of the breeds that can be left alone. Now, however, her bladder is small, her attention span is short, and you should find something to keep her occupied during the day. Are you talking about doggy day care when you mention "kenneling her"? If you are talking about leaving her alone in a crate, that is not a good idea. Having someone else take care of her the first few months when you are at work is a good idea.