Even though the power graphs may look the same, there are two distinct kinds of spiky power. One is unintentional meaning you are unable to hold a steady power and the second is the on-demand spiky power that is very common in actual bike races.
If it’s just happening by accident, it’s bad. Its either a sign you can’t ride steady or, you’re starting to get in over your head on pace and starting to struggle. Spiky power is less efficient than a steady power. However, if you are you going to do hard competitive group rides or especially if you’re going to race, the ability to output repeated spiky power efforts over a longer period of time is fundamental to succeed in competitive cycling.
All that being said, her power graphs look pretty normal for an outdoor ride (or hard Zwift ride)