I'd like to discuss potential changes should Ivara have a rework before her prime released. She's my favorite frame, so I'm biased. But having over 700+ hours, I like to think I know a bit about this topic.
A fine mid-ground passive. Knowing where enemies are located is always good, especially for squishy, sneaky frames.
Ivara has four arrows that she can use. Each has a decent starting AOE and duration, making this my personal favorite ability to build around.
Ivara's arrow that makes an AOE invisibility sphere. This arrow is arguably her best support ability because it allows the players to revive allies, rescue targets, and pets in peace. It also provides cover for hacking consoles too. It gets more useful with the 100% status resist augment as well.
Ivara's arrow that causes enemies to fall asleep within the AOE area. This is her second best support ability, and with the right build, one can easily put a large room to sleep with 3-4 arrows. And we all know a CC'd enemy is almost as good as a dead one.
Ivara's arrow that creates a dashwire between two surfaces. There are a few rooms this ability is useful. Otherwise, it's faster just to use parkour. The 100% crit damage from the augment is nice for some builds.
Ivara's arrow that is probably the most useless, both in squads and in solo play. It makes a sound that the enemies slowly walk towards. While it doesn't fully alert enemies (only putting them in minor alert), it might as well make the enemies in full alert with how easily they can spot players in this state. Minor alert is only useful if everyone in a squad is invisible because they will ignore the sound if they see one player. Her cloak arrow and her prowl ability are more useful for getting around enemies.
Ivara takes control of a single projectile. This ability is fun for a niche build. Projectile speeds can make it hard to use, however. Energy use is extremely high.
Ivara goes invisible and can steal items out of enemy pools. While the slow movement of this ability is a drawback, the pros definitely outweigh the cons. The extra headshot damage can make any gun stronger. Her ability to walk through laser tripwires with the augment makes spy missions trivial compared to her base invisibility. While invisible, she also has a pickpocket mechanic. While it is a fun mechanic, it currently has some issues. Although, I like the fact that Ivara has to stay near an enemy to steal an item, the time it takes to steal anything is too long. Also, if another enemy walks too close while she is pick pocketing, her tether can switch to the new enemy stopping her current progress in favor of the new enemy. Although this can partially be mitigated by building for steal speed, I believe fixing the speed and the tethering of this ability is much needed and will help put her on the same playing field as Nekros or Hydroid.
Ivara calls her exalted bow, Artemis. It has extremely high damage per use and has the ability to use her quiver arrows from it as a secondary fire. It doesn't get much better than a bow that fires either a single nuke arrow (with an augment) or up to ~15 arrows per shot. It is a great ability when built for damage even in sortie levels. Even when it isn't build for damage, it is a great weapon for pre-sortie enemies.
Overall, I think Ivara is one of the best well-rounded frames. While she has never been the best in any category in terms of what she can do, Ivara is definitely good in every category (except tanking) and every mission type available. With that in mind, I believe there are only a few changes to her noise arrow and prowl that would be welcome.
First, remove the noise arrow or change the arrow to something more useful. My suggestions would either be a silencing arrow or a cypher arrow. The silencer arrow could silence enemies and guns within the area of effect. The cypher arrow could hack terminals or doors from a distance when you shoot it. Either option makes more sense for a stealth/sneaking frame that doesn't make much noise anyway. Personally, I would like to see the cypher arrow that hacks terminals from a distance as it would mesh well with navigator. It would be fun running that in spy missions as well. Making the timer decrease at a quicker pace or having less time at the start might be a way to balance this arrow.
Second, prowl needs to pickpocket from multiple targets at once. The ability is too slow to be on par with Nekros or Hydroid. Even if Ivara is built for speed pick pocketing, she will never keep up with the other two. Also this would fully mitigate the tethering issue that she currently experiences. If DE added a flat cost per target or increased the time overall to accommodate this change, Ivara would be much more useful for farming resources.
Just as a bell and whistle change, it would be nice to have an effect to see the range of Sleep Arrows and have better speed control on her Navigator even at the cost of more energy.