small doses of either Karo syrup or Apple Juice would be helpful because the higher level of sugars pull a little more fluid into the digestive tract and make the bowel movement a little more loose. Just make sure you are giving extra fluid to compensate for this so you don't end up making her dehydrated. I wouldn't, unless needing to take a rectal temp. put anything other than a suppository in the rectum, as if she is truly constipated and tissue is taught you may accidentally cause a rectal tear. Add a little more fruit to the diet for a slower, gentler way, baby prunes work wonders, but watch out for bananas, even though higher in sugar, they do seem to slow things down.
Also when she seems uncomfortable, you can help her intestines out by laying her on her back and bicycling her legs, helps move things around and make it easier especially before she is walking much.