Sexing juvenile bold jumping spiders

[Noah Clark]

Hello! I'm new here. But, I've been enthused with jumping spiders for a long time. Here in Pennsylvania, bold jumping spiders are very common. I'm raising 5 of them, all juveniles, and all are slightly larger than a common house fly. The thing is, I'm hoping to get a male, as I've only ever had luck catching adult females, so I captured juveniles hoping for different results. But I'm impatient. I wanna know or have a general idea what sexes they are now. Also based on them all being similarly sized to a common house fly, what instar are they likely in? About the sexes, what could I look for in juveniles to distinguish them? Is there any difference between a juvenile male and female at all?
I will upload photos of 4 of the spiders upon request, as one of them has setup a molting sac and has been in it for a few days.

 

[Ungoliant]

The easiest way to sex them is to wait until they mature. Males have swollen palps and are slender in comparison to females.

This site has information about the species and a photo gallery of males, females, and juveniles.

 

[Little Grey Spider]

Males are easier to distinguish younger because the palps become visibly bulbous at the penultimate molt. Females don't get an epigynum until their ultimate molt. So as Ungoliant said, waiting until maturity to determine the sex is best- unless you're very experienced with it. I used to think you could tell by the stripes on the ventral side of the abdomen, but I was proven wrong on that theory last year... If you'd care to post pics of them we could guess, but it would really be just that.... a guess.