We did a 9 hour flight and on the way, she slept on me and sat on me/my husband in between. That was also a night flight. On the way home, she was up more, but we took turns holding her. We also asked to be placed next to an empty seat to bring her car seat on. They accommodated that! I just came back from a 2 hour flight, and I had her as a lap infant. She slept most of the time or fiddled with the papers in the seat. I personally wouldn't pay for a seat for an infant. Even when I got to bring the car seat on, she wanted to stay with me. But it's common that they'll place you next to an empty seat for the carseat if you ask ar check in!
Snacks, books and toys also help pass the time if it's a short flight!
We took a flight at 7 months.. she would not nap. She was nonstop moving. It was so uncomfortable!We didn’t book her a seat, the biggest regret. I would never do that again. We also buying this for our next flights. https://www.flyawaydesigns.com/products/flyaway-kids-bed?variant=30365438705699¤cy=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&tw_source=google&tw_adid=674896105084&tw_campaign=20573454195&gad_source=1&gbraid=0AAAAAClIG-4uLVCHZmeP4Np1iXMsrtKAk&gclid=Cj0KCQjwi5q3BhCiARIsAJCfuZnnbcl6kmNsjOgXIj_Ey3PNuMzzUgbB_tuW0HRATbAY5gr8hUBPUwkaAhuUEALw_wcB
We booked my daughter her own seat when she was 1.5 for a flight from Ohio to Florida. Definitely worth it in my opinion. She was able to sit when she wanted and lay across us when she wanted to sleep