Would love thoughts and opinions from other career driven mums

Context, I’m 1 month back to work with a 7mo. I work from home and my husband is on shared parental leave so it’s a brilliant set up for us. Very lucky. But returning to work was hard, lots of change, my boss left, new CEO and COO who is now my boss, new hires, new changes to our product etc. it’s been hard to catch up… and my baby doesn’t sleep. I’ve been operating on very little and my brain is so slow and tired and fuzzy. Initially I was like I can’t do this, I need to go on mat leave again or cut my hours down but decided to wait for some of these changes to happen. Which they now have and I’m happier with them than expected. Here’s the kicker, my new boss has asked if I’d be interested in a more senior role. I definitely don’t have the experience and I was candid about that and I’d have a lot to learn. I’d have to manage my current peers who I’ve very close to. But I’m someone who always wants to learn and progress and take opportunities. But I feel like I’m operating with a different brain currently and have such imposter syndrome. One thing to add is that the new role, whilst more senior is far more interesting to me and aligned with my skill set even if above my level. What do you think? The promotion is completely optional but I doubt someone else would take the chance on me for a role like this for some time. Thanks for reading 😂