I have a canon S3 so I hope I can help.

Sports mode is mostly for outdoors like biking, racing ect...

I'd use auto for those indoor shots & put the ISO up to high or 200 if you must.

Don't put the ISO on too high or your photos will end up grainy unless it's outdoors.

Like said you may also adjust the shutter speed on other modes but you might have to read about it first.