This thread reminds me that there are some other famous Russian witches who definitely flew: in Мастер и Маргарита, Margarita temporarily becomes a witch and flies on a broom, while her maidservant Natasha rides a flying pig (actually, a neighbor who was turned into a pig). And in the 1967 movie version of Вий, the old witch (who resembles Baba Yaga, but is played by a male actor в травести) causes Leonid Kuravliev to fly, while riding on his shoulders.

Seraph -- тоже в немецкой сказке "Hansel and Gretel", ведьма-людоедка питается детьми, а она не может летать, и вообще не гоняется за жертвами. Эта ведьма привлекает детей к себе тем, что она живёт в избушке, построенной из кекса, печенья, и конфеток. And although Baba Yaga didn't have such a delicious house, she didn't go hunting for children -- the young heroes and heroines came to her (sometimes because they were lost; sometimes because they needed advice).

By the way, I first discovered Russian fairytales when I was about 10 years old, in a 1966 Soviet-published English edition by Ирина Железнова. (My parents bought the book for me when they visited the USSR as tourists in the early 1980s.) As an adult, I've read some of these stories in the original Russian, and apparently Zheleznova took some minor liberties as a translator. For example, in the version of Василиса Прекрасная that I read in English as a child, Vasilisa's magical doll summons ants and mice to help with the huge task of sorting the wheat grains and the poppy seeds, but in the Russian original, it's not explained how the doll managed to sort the seeds.