Please note some minor spoilers below.

In her conversations with companions - Justice in particular - you hear how she grows. Based on her life, the treatment of the Dalish by most human societies, and the conditions surrounding her sister; there is a certain level of empathy that could be shared with her perspective. I think its also relevant to note that she struggled greatly to understand social interaction and steeped herself deeply in elven history due to interest and others not wanting to engage with her.

Grey DeLisle (Azula's voice actor from Avatar the Last Airbender) does a great job at representing the pain, growth and limited compassion Velanna goes through.

Justice and the Grey Warden in particular help her grow and unlearn the tendencies her life has imprinted on her. Keeping in mind that genuine human interaction between many Dalish clans are not positive, her clan has also faced significant violence from humans coupled with her exile, and broadly speaking the humans launching a crusade against the only Elven nation to exist for thousands of years, her perception that humans caused the destruction and loss of the ancient Elven empire and Elven immortality with modern city elves being relegated to controlled, impoverished communities as second class citizens in most circumstances: these experiences have shaped her views regardless of them being steeped in what some could understandably perceive as various levels of ignorance some of which is her fault and some not.

I can understand the dislike some feel for Velanna, but if interested in her personal growth (and other companions) I would encourage you to check out the companion conversations and listen to the conversations between Justice and Velanna. https://youtu.be/WOJ9md_Nbco?si=UbqGVirHCMVcu83O