Since she is new to you, she might be shy and won't want to drink in front of you. With a bottle, the level would go down so you can easily see if she is drinking. While bowls still go down, it can be harder to see small changes. You could try measuring the water and then remeasure it in a few hours to see if it has gone down any.
If she is used to eating veggies, you can give some soaking wet. This helps get water into her. Also keep in mind that if she is getting moisture from veggies she won't drink as much from a bowl or bottle.
If you are really concerned, you can try syringing her some water. Get a small syringe (you can try to baby aisle at a store for one) and fill it with water. Have her on your lap (a towel is good as this can be messy), and gently give a bit of water at a time. There is a spot on the side of the mouth between the front and back teeth that you can put the syringe in and she won't be able to bite it. Be careful giving water this way and only give a small amount at a time and give her a chance to swallow.
Some people will give a dish of juice mixed with water to encourage them to drink. It is important to also have fresh water available.