The usual litany involves questions about:
Budget
Musical style
New/used
Location (affects availability)
Combo amp or head plus cab
Effects modeling or none
Tube or solid state
So, let us see...
Budget: I'm going to guess my MiL would be happy to be able to drop $100 on me for the "big present" for the holidays.
New/used: I'm perfectly happy with used, and expect this would get more bang for the buck.
Style: I'm not likely to be playing any really seriously heavy metal - some 80s hair metal would be the limit there. Otherwise, the folkier end of the rock spectrum.
Location: I'm actually thinking to send my MiL to online sources. I'm in Boston, she's in New Jersey, so major metro area, East Coast.
Combo vs amp/head: Portability isn't that much of an issue, as I don't expect it to travel much, and my versatility needs are still low, being a beginner. Combo is likely the way to go, as they're simpler.
Effects Modelling: I can add much of that with pedals and such as I go, right? No need to worry about putting it in the amp now.
Tube vs Solid state: No current preference. I understand that tubes give somewhat cleaner tones, which is probably my sound preference. On the flip side, with solid state, I never have to replace a tube. Solid state is probably cheaper, and for now, that may be the best bet.
Just to be clear - anything that has an actual wattage rating, as opposed to running off a 9-volt batter, is probably going to be an improvement in my equipment.
My understanding (someone please correct me if I am wrong) on power is this. I don't expect to play really loud very often. It is a small house, and it fills with sound easily - though the image of cranking up to play the Star Spangled Banner on the 4th is really enticing, that's not likely to be my standard mode of play However, I'm also aware of some of the characteristics of amps - somewhat ironically, having the ability to do power also means that it will generally sound better when played at lower volume. So, while I might not need the volume of something over 15 watts, a 40 watt amp will likely sound better, even with all other things basically equal.