"Her experience is so many."
Translation:Pengalaman dia banyak sekali.
The English sentence should read "She has so much experience" You can't use "many" with something that is not countable in this case "experience". You could write "She has so many experiences" but it has an entirely different meaning and experiences (e.g. life events) are countable.
I took "pengalaman" to mean experiences as life events, milestones, memories, etc. It's based on the word "alam" (nature), so I assume "pengalaman" can be used in a number of ways similar to "experience" or "perceive/perception" in English. What we acquire from experiencing and perceiving the world that we are exposed to through our senses. Which can also encompass things like professional experience, depending on context.
But either way, the English sentence is not very good at all. It could be improved with "She has so much experience", "She has a lot of experience", "She has many experiences".