Firstly 
and 
- you need and deserve both!
You will know that 2.8 is absolute peak age for tantrums from any toddler, and that the lengths many secure, non adopted toddlers will take things to can be pretty epic. That said, with my adopted kids I have tended to find that normal developmental stages are more intense and/or persistent, because they have much bigger and scarier emotions that they struggle to regulate. So you might well be having toddler tantrums 'plus'. Time will tell whether they pass as they do in the normal developmental stages, or whether you and DD need a bit more help. If you do, Theraplay might be a really good thing to consider and you can now access it much more easily through the new Adoption Support Fund.
You sound as if you're handling it pretty well if your score is one or two a day for five minutes. DS at 2.8 could go on for hours, as could DD (this may be a reflection on my standard of parenting 
)
All the normal advice stands in my experience - avoid hunger or tiredness like the plague, pick your battles, stay calm, be consistent but not over demanding in your boundaries and expectations (cf picking battles), ignore ignore ignore. Two choices both of which you are happy with can be a good tactic 'eg do you want blue jumper or red jumper?'
Have an open mind on how to handle the tantrum. For many adopted kids there is very good reason not to put them in their room or use the naughty step - they have overwhelming feelings of shame and are scared of losing you, so further exclusion just makes it all worse where it wouldn't for a securely attached little one. however when DS was kicking off the prescribed 'time in' just escalated everything - too much emotion and he couldn't bear anyone getting involved. Only answer was to get him into a safe place, which tended to be his room, and let him ride it out. But never to make that punitive, and lots of cuddles and re attunement as soon as he was calm.
Put things out of reach that are going to damage her or themselves if they get thrown - sensible damage limitation.
Toddler Taming is a good general book. What Every Parent Needs To Know by Margot Sunderland is a nice attachment and neuroscience focused one.
Best of British!