- that you avoided significant weight gain over the tax season by generally sticking with the program
- that you're getting back to the program now that you feel you can focus on it
- you're noticing the evening hunger (see how it goes: eventually that evening hunger will lesson or, if it doesn't, on days you're really hungry, you can have a small snack, around 125 calories - if that doesn't work, we can try other tweaks)
- that you're trying to plan ahead for the tip with your sister: one options is you can have a glass of wine (or one drink) in place of the evening carb, but that can leave people feeling a bit hungry and also alcohol can actually stimulate the appetite - on the other hand, sometimes an enjoyable evening distracts one from eating so you be the judge); also, yes, you may want to just have a cheat day or 2 when you're with your sister - you don't want to feel constrained to the point where you're missing out on some of life's best pleasures when you can enjoy the time yet also, in the big picture, stay on track to reach your goals.
Yes, 20 pounds is a wonderful goal - it is a very worthy achievement and a great success - and sure, if after that you can lose 40 pounds, even better.
It seems you have a great attitude and approach - keep it up!