Differences in Twin Toddlers Developmental Milestones

All kids develop at different rates and with twins, it's easy to see their developmental differences when they hit major milestones at separate times. My twins have always hit their milestones at different times and I've always highlighted those in my monthly growth posts. Now that the girls are full-fledged toddlers, their differences are a lot more obvious but still follow the same trend. I'm writing this post to document the developmental differences in my twins at 20 months and what I'm doing about it as a parent. As always, my hope is that this post will serve as a useful resource to some other twin parent.

Types of milestones 
Social and Emotional - Getting skills that improve self awareness and self regulation. These milestones are subtle and parents have to stop and watch closely to see them. These come easier to twins because they've always had a playmate around. With my twins, I noticed that they graduated from parallel play to interactive play earlier than their singleton peers
Language/Communication - Seen in use of words and signs. Spice is significantly ahead with regards to communication development. She probably uses at least 20 more words and signs than Sugar does
Cognitive - Skills that highlight learning, thinking and problem-solving. This is noticeable when toddlers imitate words, identify objects in books, use objects for the right purposes and respond to instructions correctly. Both girls are at par with each other in their cognitive development 
Movement/Physical Development - Physical milestones are the ones most easily noticed by caregivers. E.g rolling over, crawling, walking etc. Sugar is very obviously ahead of Spice when it comes to movement and physical development. She runs, climbs and descends the stairs at more than double Spice's pace

What the twins do with their developmental differences? 
Language and communication: Spice helps Sugar out in following instructions. Sugar imitates Spice's words and signs until she figures them out for herself
Physical and movement: Sugar always backtracks to her sister and hangs out with her for a bit before running ahead again. Spice watches and learns from her sister's actions like climbing the high chair and turning off light switches and balancing on the edge of chairs and opening drawers, doors and cupboards.*insert mama rolling her eyes here*

What do the parents do with the twin's developmental differences?
*  Don't assume that they have the same linguistic abilities so we take time to demonstrate to Sugar what we need her to do versus assuming she understands our instructions and is just ignoring us
*  Don't compare their abilities or lack of. I believe that splitting them into 2 different classes in daycare will also help prevent this happening with their caregivers. We also firmly discourage any attempts to frivolously compare the girls to each other. In other words, we'll listen to a caregiver who has genuine concerns but will not accomodate a person who compares them for novelty and "fun"
*  Slow down the pace for Spice and ensure she doesn't hurt herself or get frustrated trying to catch up or play daredevil

This is a longer than normal post but one that I'm happy to share. I'd love to hear your take on developmental differences between twins as well.

Have a nice weekend y'all!

Resources for further reading
PBS whole child page
CDC milestone page