The way I taught mine to roll over was having them go into the down position...with a yummy treat(chcken or cheese), then turn your hand in a circular motion saying "roll over, roll over"...get closer to her body so you are slightly rolling her over with your hand /arm. Give her the treat as soon as she goes over...and of course big praise. (you could even sing the kids song while saying "Roll Over ,Roll Over,...so they all rolled over and one fell out...three bears/Yorkies in the bed and the little one said...roll over, roll over) I know it's crazy, but that's the Pre-K teacher in me.
Crawling is easier.... get her in the down position, then drag your treat hand on the floor while saying "crawl, crawl" Make sure she stays in the down positon. Even just a little crawl deserves a treat and praise. She'll get the idea. I don't have a song for that one.