Well, I have asked such clarifications in the comments, but lacking them, I realized it may actually be part of an answer.
Find out whether you actually have a problem
It is not clear that the other players are annoyed or bothered at all. Ask the other players if that is really how they are feeling. If that is how they are feeling, it may be a case for the players to talk between themselves, no need for you to even step in.
If it is you who is bothered, then, why did you make an encounter that was solvable through diplomacy if you wanted a combat? Put fanatic cultists or beasts that don't even understand languages next time.
If you do have a problem and your players are unable to solve it by talking to each other, then...
Align the expectations
If some members of the party want combat, and others want to persuade, this is a problem of expectations not aligned. Either you will need to find a solution that works for everyone or the players with each mentality should separate and play different games with different styles. It is a completely acceptable outcome: it happens when some want to play one type of game and others a type that is completely contrary to that.
A comment on the system
So, from your wording, it looks like you are playing D&D or a D&D-based game. D&D is combat-focused. It is usually ill-advised that you make a character that is actually useless in combat, or play this system if you do not like combats (as may be the case for the player). You mentioned she is the most experienced one, so she should really be aware of this. But again, this is guessing the system and I will exclude this section if it is not D&D that you are playing.
To be clear: While you certainly can play a combat-light D&D, it is not the default expectation of the system. So, it is worth discussing with your players about their expectations about the campaign and about the system. You may find that other systems fit better for your group.
Find a middle ground
So, how to find a solution that might be good to everyone? Find a middle ground. Maybe, instead of completely defeating all enemies through persuasion, your talkative Bard was able to convince some of the enemies that they should not fight. These will get away, but others are strongly convinced on their own believes and will fight. The Bard was able to be useful in combat through a non-combative manner, and the remaining players will be able to actually have a fight - the Bard included, obviously, but without much spotlight since it's clearly suboptimal for combat.
Another possible middle ground is simply balancing how many encounters can be solved through persuasion and how many can be solved through combat. Eventually the Bard will single handedly finish an encounter through persuasion, sometimes she will not. If she can't accept that some combats will happen, and the other players really want combats, then she's surely in the wrong group and most likely in the wrong system.
If violence is not the answer, you are asking the wrong question
I used this phrase as a joke in a comment in other answer, but this actually fits here: An encounter is a clash of goals, a clash of motivations, and ultimately it is about answering some dramatic question. "Will the player characters survive?", "Will the villain succeed in sacrificing the souls of the whole village?", etc.
If you want an encounter that leads to combat, you need to make the right dramatic question, one that can only be answered through violence, i.e., through combat. Maybe the villain is unreasonable, and the only thing that would convince him to change his mind is something that the characters are not willing to give, because it goes strongly against their believes. Or maybe the encounter is just a bunch of T-rexes that don't understand "human" language.
The other players can be proactive
Ultimately, if the other players wanted a combat, they could have gotten one. In a recent D&D session of mine, the Bard was trying very hard to persuade the villains, and slowly he was managing to do it, but it was taking minutes. The Rogue of the party simply drew his bow and declared "I attack". Combat ensued. Nothing the Bard can do about it. Surely, it may lead to a frustrated Bard, but the Bard spending minutes trying to convince the villains also was leading to a frustrated everyone else.
The point is: the other players don't need to sit down and watch someone have the spotlight for the entire session. They can be proactive and take it. They can, later, explain that they were feeling bored and wanted to play too, so he decided to do that. It actually led to the first point I made: the players ended up talking about their actions and expectations and the Bard realized he was being annoying sometimes.
If you want to reward the Bard player for their attempts, you can even give surprise or some other mechanism in your system to the party, as the Bard was distracting the enemies and they didn't notice the Rogue drawing the bow and attacking.
This is a very specific example in my own group, and should be used very carefully in order to not just make the Bard player extremely unhappy, but if it is a recurring problem, it may lead to a good solution. If nothing else, it shows to the Bard player how upsetting it is to have the choice of how they wanted to handle the problem taken away.
PS: This is quite passive-aggressive. I strongly recommend sitting down and talking about it. I am just providing this as an example of things solving themselves without the DM even needing to intervene.