Set during episode 7 "Human for a day" (I haven't seen episode 8 yet so no spoilers please). Just Alex taking care of her sick little sister :).
Kara sniffled as she wrapped the duvet tighter around her. She felt like she had never appreciated being able to breathe through her nose properly. How did humans cope with being sick? Alex had checked her over and said all things considered this wasn't a terrible cold, but Kara felt like death warmed up. She just wanted to sleep all the time, but every time she tried her mouth went dry and icky from having to breathe through it. It was official: she hated being human.
Alex came through and placed a steaming mug of chicken noodle soup on the table in front of Kara before plonking herself down beside her.
"Still feeling rough then?" She asked. Kara nodded, giving a little groan. She reached forward feebly, and Alex couldn't help but laugh. "Here, I've got it." She said, carefully taking the mug and handing it over to Kara.
"Thanks." Kara said, wincing at the sound of her own croaky voice. Alex placed her hand against Kara's forehead and frowned. She was still running up quite the temperature. If it continued she would have to take her to the DEO for proper medical help. She wasn't going to do that unless there were no other options. She still didn't completely trust Henshaw and she didn't want Kara near him unless she was there. Kara rested her head against Alex's shoulder.
"Thanks for looking after me." She whispered. "I know I must be a bit of a nuisance right now. You've got enough going on trying to work out what happened to your dad without me adding to the drama. I really appreciate it." Kara said sincerely. Alex rested her own head on top of Kara's.
"You're not a nuisance Kara, you're my little sister. We both know it's literally my job to look after you. But even if it wasn't, I still would." Alex knew how stressed Kara was about all this. She knew she was worried unlike her cousin that her powers weren't coming back. "You're rundown, Kara. Your powers are going to take a while to recharge. The more you stress about it, the longer it's going to take." Alex pointed out. Kara sighed, sitting up and moving to lean against the arm of the sofa.
"That's just the problem. I don't have time. National City needs Supergirl to protect them now. Not in a few days. I'm letting everyone down." Alex took the soup from Kara and put it back down on the table so she could take hold of her hands.
"Kara, look at me." Alex said gently, but with authority. She waited until Kara was indeed looking up at her. It hurt Alex to see the deep disappointment in her eyes. She shouldn't be feeling all this burden alone. "You're not letting anybody down. The reason you're in this state is because you gave everything to protect this city already. You've earned a break to recharge. The emergency services and the DEO can handle things until you're on your feet again. You should be proud of yourself. You've only just started being a hero and you've accomplished so much. I'm certainly proud of you." Kara felt herself blush a little under the praise.
"You are?" She asked timidly. Alex nodded.
"Of course I am. As well as terrified whenever I see you out there fighting in that costume. I hate seeing you get hurt. It goes against every big sister urge I have not to go and whoop ass, even though I know most of your opponents could squash me like a bug. In ways I'm a little relieved you're off the job for a few days. At least I know you're safe. So, rather than you looking after the city, let me look after you for a few days. You've earned it." Alex stretched forward and grabbed the remote. "I've not got any plans for this evening. What do you say we binge watch The Fresh Prince of Bel-Air. For old time's sake?" The Fresh Prince was one of the first TV shows Alex introduced Kara too and it quickly became their show together. Kara smiled. Maybe a quiet night in with Alex was just what she needed to get better and be able to help again. She smiled and nodded, sticking her feet on Alex's lap. There were plenty of times Kara missed her home planet, as well as her parents. But she knew had she not come here alone she would never have gotten her sister. Then who would she have to binge watch old TV with when she was struck down with human illnesses?