What you can do is take the cushions off the couch and arrange them behind her or use large stuffed animals - anything that breaks the fall but you will need to be watching her because as she falls and tries to roll she will get stuck. Just using the blanket she will have a better chance of rolling herself back over.

One of the exercises they did with my own special needs daughter was to lay her on her tummy on a large exercise ball - hold her hands and then push it back and forth, rock it slightly side to side. She will be learning vestibular balance in the way she needs for crawling - and it is fun. Yes the other kids will want a turn too. Later you will put her on the ball and hold her feet and do the same things - rolling it forward and in theory she is supposed to develop the instinct to put her arms out as the balls goes forward - again supporting herself for crawling.

Crawling like a snake is another one done laying the child on her tummy and then moving opposite arms and legs forward then put hand under body (through legs and support tummy) to push body up into position for where the hands now are.

If she hasn't played much arm strength will be an issue. Hold things above her head and encourage her to look up and reach for them. Make them come from the sides to the centre and then to the other side. Take note if she doens't look and follow (track the movement of the object) as this is a sign of issues visual or mental.

It will be nice when you have more time to just play because she will be at the stage where she needs a lot of adult leading - just not adult doing which she may have had in the past or just sitting in the name of play and watching life pass her by which is more likely. I so miss having babies in daycare - enjoy.