Some ferments get more bubbly than others. How long has yours been going? Did you use chlorinated water? You should notice a slightly sour or sweet-sour smell after 3-4 days, bubbles or not. If you do, you're on the right track, if not wait a few more days. Temps below 65F can really slow down fermentation...it might still be happening, but harder to tell. Give it more time.
For the record, you don't need ACV with the mother. Or any vinegar. Whereas I think ACV with the mother is nutritionally superior to pasteurized vinegar, you would be using such a small amount of it in fermented feed, that it really makes no difference. The main reason to use ACV (or white vinegar or rice wine vinegar, etc) is to slightly lower the pH (make it more acidic) so that the beneficial bacteria get a leg up as establishing themselves as the dominant bacteria. Usually they will win anyways without vinegar, but a small bit of vinegar will hedge your bets.
Let us know how it goes.