E.B.F 🤱

Hi mommies my baby is about to be 2mths at the beginning of January. I have been exclusively breastfeeding her only!! But now that she’s gotten a little bigger she just isn’t get full like before. Now she wants to be eating every hour in a half and she’ll be feeding for 20min long. I do want to try & supplement a little bit of formula to see if that’ll help her get full but I’m so scared that she’ll prefer the bottle more than my boob.. question is how often should I supplement the formula & what bottle/nipple brand would you moms prefer ? 🤔