I still disagree. My 12yo stepson has quite a few video games. He cannot play them when his grades are bad or before he finishes his homework...but my bio kids also cannot use them without asking or when he isn't here. He owns things outright, but there are rules for their use based on his safety and well-being. My 6yo DD owns a LeapPad, but can only take it in the car with special permission and can't use it after bedtime...but her baby brother and other kids can't borrow it without asking. The fundamental way that OP plans to use this ipad is NOT as DD's that she will agree to share, but rather exactly the way I use MY ipad, letting my kids borrow it at will within the confines of their screentime limitations and behavior. I think it would be unfair to tell a child this item belongs to her and then treat it like it belongs to the parents. My children both knew the distinction at 3, and even if this particular child doesn't get it yet, the goal should be to teach her and guide her to the next level of understanding.
I guess I am not following why the OP cannot simply explain the use of the ipad, as the OP wants it, to her DD. I didn't see an answer to my question about whether the FIL forbade the OP or her DH from using the ipad because he wanted to give it to the DD. That would be really really odd to me, as I am pretty sure I more fully articulated above (basically, because the DD could not possibly be able to use the ipad totally on her own). Re the bolded, I don't understand why the DD cannot be taught that for this item, she gets to use it in the ways her parents tell her she can. As several PPs mentioned, lots of kids "own" various objects but have different rules attached to these objects depending on lots of factors.
Also, as a PP pointed out, the OP seems to be fine with the DD "owning" and exclusively using the inferior ipad. Just not the nicer one. It's not about the OP not wanting her DD to have an ipad. To answer the initial question in the OP, yes, I think that is unreasonable.
I don't think the issue has anything to do with the FIL dictating how the iPad is
used. The issue is who
owns the iPad, i.e., to whom the FIL gives it. I realize that you may not consider this distinction important, but others, including the OP, clearly do.
RE: children's ownership of items.
Imagine for a moment that the OP has two children, Child A and Child B, and FIL chose to give Child A a doll. It would be perfectly reasonable for her parents to set rules on use of the doll: when and where she may play with it, how she is expected to treat it (e.g. don't throw it across the room, it must be put away in this location after playtime), taking it away as a consequence for misbehavior, etc. It would also be reasonable for them to decide that this particular doll was not an appropriate toy for Child A and not allow her to keep or play with it at all.
However, would you consider it reasonable for the parents to decide that the doll given to Child A will instead belong to Child B? I would not. If FIL gave the gift to Child A, then the parents may refuse the gift on her behalf, but taking something that Child A owns (because it was presented and accepted as a gift to her) and simply decreeing that it will instead belong to Child B would IMO be wrong. This has nothing to do with FIL forbidding Child B from playing with the doll. It has to do with who owns it.
Also, if the doll belongs to Child A (because it was a gift to her), I would expect Child B to get Child A's permission to play with the doll. The parent's might set rules about the children being expected to share their toys, but I would expect those rules to work fairly in both directions (i.e., Child A would not be required to share her doll without also benefiting from Child B being required to share a desired toy with her). Personally, I see a subtle, but important distinction between "This is yours, but you are expected to share it appropriately" versus "This is 'yours,' but others can use it whenever they want without your consent." The former is an expectation of behavior for the owning child: the owner still has final say over how the item is used, but may face consequences based on how they handle this. The latter IMO negates the principle of ownership: the "owner" has no control over how their possession is handled/used. It also pretty much negates the concept of sharing: there's really nothing "nice" or virtuous about sharing one's possessions if you aren't allowed the choice to do otherwise.
RE: the child owning an iPad at all
That was not what I gathered from the OP's posts at all. My impression is that the OP was fine with her child owning a high-tech children's toy, the Leappad. She is also fine with her child
using a grown-up toy, the iPad, with the permission of its owners (OP and husband). If the family owned two iPads, there would be less conflicts with two people wanting to use the same iPad, which could be a minor benefit for the child in terms of getting iPad time. However, I got the impression throughout the entire thread that the OP is not comfortable with the child owning either iPad (newer or older) outright, and neither would be designated for the exclusive use of the child. I also got the impression that the OP would much rather have her child receive the Leappad instead of the family receiving the 2nd iPad, but that she was trying to be flexible since the iPad would be easier and cheaper for the FIL.