Bum shufflers as a rule walk later than crawlers I was a bum shuffler and also a cubby baby mum just said I was too fat to walk lol anyhow I walked at 18 months.
My 3 year old didnt walk till she was 21 months and also barely spoke at 18 months she couldnt even follow simple instructions like give me your cup or go get the ball she would just look at you as if you were stupid. She only started saying Mummy at around 18 months. We were reffered to the hospital basically because when she was 18 months she had a febrile convulsion and was admitted then through the normal questioning they asked if she was still running around and talking ok and I said well she doesnt walk and doesnt talk this was at 17 months they then ran around mutttering to eachother and sent doctor after doctor in and decided she needed referring. We then attended appointments at the hospital where she was diagnosed with developmental delay by the time she went back for her next appointment she had started walking but not confidently and was saying 1 or 2 words she was then sent for speech therapy. Fast forward to now and she has been discharged from the hospital they said her large motor skills are still slightly behind other 3 year olds in that she finds steps kerbs difficult and she cant jump (very cute when she tries because she doesnt leave the floor lol) but in some of her other tests she came out above a 3 year old.
All kids are different and usually catch up in the end just because they dont walk or talk till late doesnt mean they have something wrong with them look for other things they can do as well, the bigger picture. Like play independantly, build bricks, pretend to drink from a tea set, feed a doll , scribble with a crayon, take things out of bags and put them back in, look for things you hide under a tea towel, understanding what you are saying to them ect ect ect these are all things that will tell you that your child has other understanding of the world around them
((hugs)) anyway I know how worrying it can be.