Changing her position
Women will tend to be very independent in the early phase of the 1st stage of labour. They will often walk, wander, rest and change position themselves, with relative ease. As the labour progresses (and moves into the active phase), their mobility can diminish and the help of their support person to suggest a change of position, or physically assist them, may be required. It can be very demanding to move from one position and into another in the active, and transitional phases.
You can suggest a different position, if she is becoming irritable, distressed or indicating that she needs a change. Offer her a choice of positions. She may want to move (or she may prefer to stay where she is). You will need to help her into alternative positions, take her to the toilet, and possibly in and out of the shower, or bath.
It is a good idea to let gravity assist her and the baby, so if she is inclined, being upright, walking and kneeling are best. If she is exhausted, suggest that she lie on her side, either flat, or up on a beanbag. You can still massage her and apply heat packs to her lower back or abdomen. If she is on her knees for hours, massaging her knees (or putting extra pillows under them if she is reluctant to move) can help her feel comfortable.
Avoid letting her lie on her back for prolonged periods (unless she is adamant this is how she wants to be). This can sometimes reduce blood flow to the baby, decrease the size of her pelvis during the pushing phase, and is generally much more uncomfortable.
Walking with her
Some women find walking helps the progress of their labour. Try walking with her to help move the labour along, if she feels up to it. If the contractions are not too intense (or need stimulating), she may be able to actually walk during the contraction. This can help the baby descend further into the pelvis.