The ideal beginner sight on a recurve is probably a ring sight, where the shooter just centers the target in a ring. The better versions of these use an adjustable aperture that lets you adjust the size to just fit or just see the target. That helps the shooter focus only on the target and not get distracted when taking the shot. The downside is that like a single pin sight, it's a one range only sight - unless you combine it with a target sight.
The next step "up", or maybe to the side is a single pin sight.
For multiple ranges 3 pin and even 5 pin sights are available. They work really well on bows like the Samik Sage that is drilled an equipped with threaded inserts to accept accessories.
I have this on my Samik Sage. It's not significantly different than yours - maybe just a little older. Both weigh 4-5 oz:
https://www.amazon.com/gp/product/B002KDZ6KE/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1
You can go with something like the Trophy Ridge Outlaw that adds some marking for adjustments, a level and a light for the fiber optic pins, but the weight goes up to 7-8 ounces, and I don't think it really adds much other than a whole lot of potential distraction. It's a move in the wrong direction IMHO.
The last step would be to a target sight with vernier adjustments in windage and elevation. The downsides are that a good one costs serious money (while a cheap one is just cheap), and the design isn't as rugged or protected as a pin sight as they normally extend 6" to 9" in front of the riser to increase the sight radius.
This one will cost you just this side of $300, and that's not including an aperture. The aperture can be a simple ring, a ring with a pin, a ring with various shapes, or an adjustable aperture. Range changes are done with the vertical vernier adjustment and windage can be adjusted with the horizontal Vernier adjustment.
I suggest you go to the Lancaster Archery web page and look at the wide variety of sights, scopes and apertures that are available.
https://www.amazon.com/Sure-Loc-Supreme-Sight-Extension/dp/B0060CZANO/ref=sr_1_3?ie=UTF8&qid=1515766082&sr=8-3&keywords=SURE-LOC+Supreme+550
This one is about $330 and then you need to add $120 for the S2 aperture, making it a $450 sight:
https://www.amazon.com/Sure-Loc-SureLoc-Sight-Extension-Right/dp/B00UQUC63S/ref=pd_sbs_200_3?_encoding=UTF8&pd_rd_i=B00UQUC63S&pd_rd_r=PCCDB51P2QTZJ9FX8X54&pd_rd_w=0Sh5a&pd_rd_wg=EczB7&psc=1&refRID=PCCDB51P2QTZJ9FX8X54
https://www.amazon.com/Sure-42mm-Scope-010-Black/dp/B0097W1B9Q/ref=pd_sim_200_1?_encoding=UTF8&pd_rd_i=B0097W1B9Q&pd_rd_r=PCCDB51P2QTZJ9FX8X54&pd_rd_w=tM0ts&pd_rd_wg=EczB7&psc=1&refRID=PCCDB51P2QTZJ9FX8X54----
In short, unless your daughters are interested in competing, and would benefit from a target sight, you're probably already where you need to be in terms of sights for recreational target shooting and hunting purposes. One inexpensive option you might consider is adding a peep sight to the string. This ensures the eye is in the same place every time. I'm ambivalent about them however, as you really don't gain much over developing consistent anchor points, so at best it's only a small improvement and at worst it's a crutch. Now...if I get old enough that my eyes no longer focus on the front sight pin, I may add a peep with a corrective lens in it - and that's also something you find on peeps used with high end target sights.