I’m happy but I’m sad

Ni

My baby is growing so fast will be 5 months next week. She’s literally already putting herself to bed. I give her a bottle in her crib she drinks it’s all herself and then goes to sleep. She’s able to roll over fully. Front to back back to front so I feel ok leaving her alone in her own room now, but I didn’t think this would happen sooo fast. Anyone else baby does this? Just puts themselves to sleep?