S.H.
Your routine might not have changed.
But she did.
She is now 9 months old. Not a newborn.
Development/teething/cognition/motor skills/hitting milestones/hitting growth-spurts/separation anxiety... ALL changes.
Sleep in a baby, is never static. The baby changes. And as a baby/child hits different age junctures, sleep, changes.
No baby, toddler, older child, pre-teen, teen, college kid, adult.... sleeps the same way they did as an infant.
When my kids got like that as babies, it was separation-anxiety. The Ped told us that too. It is normal developmental occurrences.
Looked at another way: it is growing-pains, for the baby/child/parent.
But happens.
And, feed on demand. At growth-spurts (of which 9 months is), they get hungrier, and intake needs to keep up WITH them. They need more intake.
Breastmilk or Formula is a baby's primary source of nutrition. Not solids and not other liquids. For the 1st year.