I don't know if my dog drinks enough water

As long as her access to water is not restricted, I wouldn't worry about how much or little she is drinking. We have a Malamute mix that had the opposite behavior when we first got her (at ten weeks). She would drink and drink and drink, up to minutes at a time if we let her. We had to restrict her access, because obviously at ten weeks, she can't hold all that water - and she would just go right back to it. Eventually, she grew out of it. We think it may have been a hoarding-type behavior, since her remaining littermate was very pushy, and her new sibling was more easy-going.