The word "amble" and its various conjugations appears a lot in stories sent to literary journals. I understand you want something more descriptive than "walk" or "move," but I don't think this is your choice quite often. Just like you've probably read not to overdo fancy words that are just dialogue tags (e.g., just use "said" instead of "remonstrated), it's maybe better sometimes to use "walk" or "move" than amble, when amble really doesn't seem to fit. I won't disqualify your story because you said "amble." Just FYI, since a lot of stories are of nearly equal merit, and every little bit you do to not make the judges squirm in their seats will help you.
Carry on writing.