My DS didn't crawl properly until 10 months. Up until then he used to grip the ground in front of him and pull himself along his belly! Our neice (DS's cousin) was born a month after DS yet she crawled a month before him (so when she was 8 months). They are both running around together on their feet now and you cannot tell who crawled or walked first!! Your 'friend' is being really lame by comparing them like that - they are individuals and do things when they are ready. Don't worry about it!!