C.K.
Don't worry - it will happen. My son turns 16 months tomorrow and is also a slow developer in the walking department. He can do it, but his preferred method of transportation is crawling, especially at home. He seems to show off more when we are outside or at a party or something. I was really getting worried because all the kids in my family (I only have 1 of my own) have walked really early. The doctor said that he is still making progress and developing normally, and it sounds like your daughter is, too.
I've been told that sometimes children are working on developing other skills such as speech and fine motor skills, and they put walking on the backburner.