If your choices are limited to the list you provided, I say the Laser hands down. Your 14 year-old will already be done with an Opti as soon as she/he figures it out (real soon). A 10 - 12 year old is in the target age group but will soon be done with it. The Opti is good for a yacht club fleet where there is a continuous supply of 10 year-olds moving into the fleet.
The Sunfish is good for girls and boys to hang out on and do a lot of flirting, which is what they should be doing when they are that age! The Laser is made for sailing and by the time the kids are 14 they are ready for it. I wouldn't worry about it not being a "family" dinghy. Chances are, one kid can't get enough of it, 2 others won't be so interested. When I grew up on a small lake, I sailed solo as much as I could on a boat with 2 sails. My brother and sister, not so much, but we sailed together as well. When you want to fit it a small boat, it works out very easily.
I was capsizing the boat and sailing away as soon as it was up again because it was self-bailing as soon as it was moving. I could easily right it alone when I was 14. I learned how to handle 2 sails single-handed very easily. Way too many adults worry way too much about what their kids can handle in my opinion. Without any formal instruction, I think it is amazing what kids figure out completely on their own. Imagination is a wonderful thing! We had a Ghost 13 for our second sailboat. When I was about 12 we had another small sailboat, but when it capsized, we had to drag it to shore to get it back upright and bailed out. My dad got tired of that real soon.
https://sailboatdata.com/sailboat/ghost-13
This is what I sailed from age 14 until I left for college. I bought a Hobie 16 when I got back.
https://sailboatdata.com/sailboat/sea-scouter
This is what we had when I was younger. It was a PIA because I sailed it always on the threat of capsize, which it would do. Then my dad would have to chase me down and drag the boat back to shore so I could bail it out and do it again.
My granddad had some Japanese business guests out to the lake one day and a few wanted to sail it. They capsized and the mast and sail slid out from the slot (very bad design, it was unsecured). It settled in the mud on the bottom 40' below and we had divers out to try to find it. They were from the local volunteer rescue squad but they quit early because the water was too dark and cold 40' down. They quickly came back to shore and tapped a keg for a long party, which is what they really came for.
My dad bought the Ghost the next season because my mom insisted that we must have a sailboat because we had a "lake cottage". My dad was interested in farming and had less interest in the lake. He bought the Ghost because it was advertised as self-bailing and easily-righted after capsizing. That meant he wouldn't be tied down being the rescue boat for the "kids". Mom gave up sailing because she couldn't keep the boat upright. Dad wasn't very good at choosing sailboats. That's when it became almost exclusively "my" boat. It was perfect. It was fun taking girls out sailing and capsizing the boat.