They could have been put under some sort of spell by the Order to forget about Hermione. In that case, they would have just gone on with their lives, completely unaware that their daughter had been taken. However, if the spell was not perfect, they might have had some strange feelings or dreams about a missing child.
If the Order didn't use a spell on them, Hermione's parents might have tried to seek help from the authorities. But since the magical world was involved, the Muggle authorities would have been of no use. They may have even been harassed by the Death Eaters or other dark forces who were also interested in Hermione, thinking that the parents knew something about her whereabouts.
She would be devastated. Hermione is a very emotional person deep down. She might isolate herself at first, not wanting to talk to anyone, even her closest friends like Harry and Ron. She'll probably go through a phase of denial, not believing that her parents are really gone.
She might be initially shocked. But being Hermione, she would quickly gather her wits and start planning. She could use her vast knowledge of magic to find her way or to signal her friends.
Harry would probably be initially cautious. He has a long - standing feud with the Malfoys. But knowing Hermione, he would gradually come around and support her. He might even see it as a chance to break the cycle of hatred between the families. Ron, on the other hand, would be more vocal in his doubts. He would question Hermione's decision, but in the end, he would also be there for her, especially if he saw how much the baby needed care.
Hermione's friends from the Ministry of Magic or other magical organizations would also react. Those who respect Hermione for her intelligence and contributions would be supportive. They might offer her more flexible work arrangements so she can take care of the baby. However, there might be some who are envious or judgmental. But overall, Hermione's true friends would surround her and the baby with love and protection.
She might have been shocked. Hermione is usually a composed character, but such an unexpected physical action from Fleur could have caught her off - guard, leaving her momentarily stunned.
She would probably be very hurt and angry. Hermione is a strong - willed character, so she might immediately start trying to find out the truth and clear her name.
She would probably be in awe. After all, she has heard so much about them from Harry. She might be a bit nervous at first but would quickly warm up and start asking them all sorts of questions about their lives and magic.
One possibility is that Hermione manages to talk some sense into her parents and they release Hedwig. This would require her to explain the importance of Hedwig to Harry and the fact that she is just a normal owl in the wizarding world.
Hermione's friends would likely be very excited. They might plan some special activities for her parents. For instance, they could arrange a little tour of the Forbidden Forest (from a safe distance, of course). They would also share stories about Hermione at Hogwarts, how smart she is and all the adventures they've had together. And they would be happy to answer any questions Hermione's parents had about the wizarding world.
She might be angry at first. She has always been loyal to the Order's cause, and this abandonment would be a huge blow to her.