seeee.. I think my mom just needs to sit down with me and look at this site. I think I would totally have her wanting one by Christmas

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I am owned by:
2 dogs, a Hahn's macaw, 2 parrotlets, 2 parakeets, 1 bearded dragon, 1 cornsnake, 2 yellow belly sliders, 1 razorback musk, 30 gallon saltwater reef, 10 gallon planted tank, 5.5 gallon planted betta tank

Rainbow boas are medium-sized boas, but IMO they might be one of the strongest and most powerful. I've handled BCCs and BCIs, BPs, and various other pythons. I've NEVER found a snake that squeezes as hard as my rainbows. It's not like they are trying to hurt anyone, they're just holding on, but they hold on TIGHT! When Talyn holds onto my arm, my hand will start to tingle. I do NOT let her anywhere near my neck anymore!! And my husband doesn't want me handling her when I'm alone for obvious reasons.
Also: yes they are beautiful, but don't expect to see them very often during the day. This was the biggest disappointment for me. They are night active (I'm not!) and during the day, they are wrapped up under the hide boxes. I only see them if I take them out in the evenings or stay up late and watch them at night. I've solved this problem by printing out nice big photos of them and putting them up in my snake room.
Rainbow boas tolerate some quiet handling (I only take mine out in the evenings and keep the lights dimmed and noise at a minimum.) They do not like to be passed around to friends. They can be tamed, but as a rule, they are not as good-natured as BPs.
Rainbows are generally good eaters, but I've had several problems with regurgitation in the males that I had. If you get a CB baby and feed it properly sized prey, it shouldn't be a problem. You'll want to have it checked early on for any internal parasites, because they can cause digestive problems. (This is true for any snake.)
Good humidity is a must. 60-80% (The high end for juveniles and shedding times). The easiest way to keep the humidity up, is to use something like orchid bark substrate, it holds moisture well. You'll need to mist the terrarium with a spray bottle once or twice a day. -- you don't want the soil soaking wet. If you use paper-towel or newspaper substrate, it will be easier to clean but more difficult to keep humid. You might have to mist the cage more often. In any case, I recommend a good moist moss box. (A closed tupaware container with one hole in the short side just big enough for your snake to get in after it's eaten a big meal. You do not need to punch more holes in it -- that will just dry it out and defeat the purpose!) Get sphagnum moss and wet it with warm water, then wring it out like a washcloth -- you want it moist, not dripping. Don't let the moss dry out.
These are all reasons that they are not considered a good beginner snake. They are more high-maintenance than others. These are just points to think about: if you really want one and you are willing to put in the extra care needed, go for it! I hope you can convince your mom.