It sounds as though she has constipation.
Breastfed or Formula fed?
If breastfed, any change in your diet?
Was she recently introduced to solid?
You can try to do massages on her tummy and also cycle her legs.
Also it seems she is beginning to recognize people and may face separation anxiety period which is normal. Just remember to make her feel secure that you will never leave her forever and ensure interaction with other adults. Let her warm up first, not just force her to others.
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