Get a genetic screening as soon as reasonably possible, and make sure all genetic flags of all types of EDS are checked, both concrete and corollary. If the mother has cEDS, for instance, don't just check for cEDS. Check for vEDS, kEDS, hEDS and more. Even if you are unable to get a concrete answer, just being told "the child has many of the genetic markers that correlate with hEDS" can let you know that there's a good chance that they'll develop symptoms at some point, and to keep that in mind.

If you suspect the child may have Vascular EDS (vEDS), it's imperative that you get a genetic screening ASAP. If untreated, vEDS can be potentially lethal, or lead to a substantially reduced lifespan.

Note down EDS symptoms as they come. Hypermobility, fragile skin, visible veins, chronic fatigue, chronic pain, dislocations & subluxation, etc. Note the symptom/trait, what they affect, and when this symptom was first observed.

These symptoms also come at different ages. For example, the hypermobility is usually degenerative. That is to say, you start out incredibly hypermobile, but as with most abled people, the condition worsens with time, potentially becoming arthritic in old age. This contrasts with chronic fatigue and chronic pain, which become most apparent at around the age of 10-15. Of course, it varies case-by case.

Once there are enough symptoms - if there are enough symptoms - to warrant a diagnosis, then it's a good idea to seek one.

And as a sort of P.S., as the kid grows up, make sure to independently check on them with time. I never complained about my symptoms until I was already an adult, since I thought the symptoms I had were normal. I was always told I was overreacting, or being just lazy & weak, or that "everyone has something like that". Because of this, I basically lost my entire childhood and formative years. Don't wait for your kid to report in symptoms, because there's every chance that they won't, even if they do. Make sure that you actively check to see if they develop any traits.