We noticed in the attached picture, a bulge / bump on our Yellow Labs front right leg elbow
It is soft and doesn’t seem to bother her.
She also has not issues running out in the yard (no limp).
Does this need to be looked at by a vet?
Will it harm her if we leave it as is?
Yep, I'd have a vet look at it if this were my dog.
Our black lab got them all over, they were all benign fatty tumors, sometimes they need to be removed but most of time they are nothing to worry about. I would have a vet look to be sure though.
On almost all cases those are lipomas, a tumor made of fat, they should be monitored periodically to prevent from damaging articulations (depending on location) or invading crucial areas like the mammary glands, also checks for any changes on size or if it becomes uncomfortable should be observed. Your vet is your most reliable source of information, specially for things like this where a physical examination is needed for an accurate diagnosis.