She's how old? What size clothes does she wear? Are they way too long when you buy jeans/pants for her?
If she is 4 and wearing size 10-12/large clothes then yes, she's way too big around. If she's 4 and wearing girls small or mediums then she's pretty much okay.
If she's flabby and looks fat then chances are she needs to do something to tone her body more. If she solid as a rock and not a jiggle anywhere on her body then she's probably okay.
There are so many variables to this that you didn't put in the question that I can't say for sure.
I have a friend whose daughter is normal height. She wears adult large in leos, tights, pants, jackets, etc...dance clothes run small and in regular clothes she's a medium to a large. She is ACTIVE!!! She dances, rides BMX and wins almost every race, she plays basketball, and more. She does hours and hours of stuff each week.
This girl looks overweight. She has a huge middle section and her thighs are nearly as big around as my granddaughters. She has a fat chubby face too. But she doesn't have single jiggle anywhere on her body. She is a ROCK! I have to make costumes for this girl because they often can't buy her the same one as the other girls her age because this girl is so huge and the other girls are from girls size 8 up to girls size 12-14. Then there is this girl.
This girl's mom frets over her diet and tells her she needs to think about what she eats and is always trying to make a difference. She is a good mom.
Then one day this mom showed me kid pictures of her and then her other kids. They ALL looked like this girl growing up! I asked her what she'd done back then and if she'd felt "fat". She said no. She was happy and played softball and basketball and soccer year round. Then as a teen she started changing and growing taller and thinning down.
She is by no means a size 2 or 4 but she's not a 18 either. She is slightly, slightly, more round than a normal looking person. I reminded her that she had looked similar, her other kids had looked similar, and this girl would likely follow the same line of growth. To lighten up a bit and let her enjoy life as a kid.