younger dd1 acts like she hates her big sis

[weeonion]

Our 10yr old dd1 adores her wee sister but sadly dd1 aged 3 gives her a horrible time.

I know alot of this may be typical of dd2's age but she is never nice to her big sister. she screams and shouts at her, tries to hit her and any attempts at kindness etc from her big sister is responded to by a big rebuff.

When dd2 acts like this, we tell her it is not nice and she is made to apologise.

Dd1 broke down last night and told me how hurt and sad she is about it. She sees other kids getting on and feels hated by her wee sis.

Any tips on what we can do?

I think its worth explaining to your older daughter that her sister is 3 and not really grown up yet so can't regulate her behaviour in the same way

I'm sure you've already explained to the older child that 3 year olds have difficulty regulating their behaviour.
Two of my granddaughters are similar in that the younger one teases, rebuffs and is often horrible to the older one. My daughter deals with it by explaining to the younger one how hurtful it is and that her behaviour isn't acceptable and then a punishment is exacted such as taking a favourite toy and putting it on a shelf she can't reach. The toy is returned after apologising properly to her sister who can then decide whether or not to accept the apology. If she doesn't accept it then younger child chooses to forfeit either her bedtime story or her Peppa Pig screen time.
Younger child is learning about consequences. Older child is learning about assertiveness.
It sometimes goes a bit wrong but most of the time, it seems to be having the desired effect..

Thanks folks. I have explained to dd1 that her wee sister is learning and finds it hard to controld emotions etc. She knows this but still gets hurt.

Dd2 does have consequences for this but it seems to have little lasting effect as yet.