Princess Peach is quite a lucky character. In Melee she was considered to be one of the best, similar in position to Captain Falcon and Jigglypuff. Unlike some of her Melee contemporaries, she didn't get nerfed to a bottom or low tier position. Nay, she has managed to still be good, due to the base effectiveness of her character. She prides herself on being an aerial master, able to float around at will. From there, she can launch a myriad of moves in succession, able to daunt many from entering the air.
Peach has no real defining moment in the match against Ike. She’s not Dedede who has a chaingrab, she’s not Pit with his arrows and she most certainly isn’t Snake with his great grenades. Her moments stem from the fact that she has so many interesting things that she can do to you, several tricks that rack up damage, kill and in general add up to be a good character.
Let’s begin by talking about Princess Peach’s turnips. She can quickly pick these up from the ground with a down B and then just toss them at you. She’ll generally glide toss them for a good distance. They aren’t super high on range, so she can’t begin to use them from across the map. These are a nuisance and deal some damage and flinching you. I suggest being able to catch the ones she throws at you, or otherwise shielding it, it won’t hurt the shield too much. She might attempt to toss them at you to ruin your recovery attempts, so beware. If she pulls out a stoned looking turnip with stitches, beware. This deals very high damage and has amazing kill power. She can also pull out a Mr. Saturn, a Bom-omb or a Beam Sword. Mr Saturn instantly breaks your shield if it hits you, the bomb KOs at like 60% and the sword gives her Ike’s range. The sword has ½ the range of a normal beam sword, but she can stop this by taunting or using her up B.
Peach’s main form of threat is her Down Aerial at low percents. This pressures shields like no other. To avoid this, angle your shield upward as much as you can. If she hits you while floating, she will often follow it up with another down Aerial and top it off with an Up Aerial for massive damage. No, seriously, it hurts. Your best bet is to DI this if you get his, but of course not getting hit at all is the best course of action! The rest of her Aerial game is certainly good enough for causing damage as well. The Nair is very fast and the Bair has decent range, the Up Air is fast as well.
Her grab game is pretty decent, albeit short ranged. Her Down Throw will be followed up on by a grab at 0%, so look out for grabs at low percents. Her other throws might be used in order to either get you off of the edge, or into the air, where she will attempt to hurt you. She might get a grab on you by using a jab (Which is just as fast as yours) and then dash grabbing.
Remember in the Marth match-up how using Aether and Marth countering would result in a pretty easy gimp on Ike? Peach can do more or less the same thing with her Toad counter. As with the Marth match, either recover low or do a reverse Aether so that you don’t hit Peach and then toad, as that will result in a stock loss most likely. You might try to use Quick Draw if the spores send you upward, however.
In Melee, Peach’s Down Smash was a very frightening thing indeed. It was capable of causing very high damage in a single use, and was quite fast! It’s been toned down a bit since then, it now only sends you on the other side of Peach with not nearly as much damage. It’s still fast, so she can pull one out to punish you. Ftilt can be using to punish a laggy attack in the exact same way. The Fsmash is too unpredictable to count on, but it either has high range lowish power, middle or the pan with low range and it sends you straight up. Her Up Smash is very powerful when sweetspotted, killing at 100% or so. The problem here is, good luck sweetspotting that.
Her other kill move is the much loved Fair, which occurs when she hits you with her crown,. This has good range, good power and can be used to gimp you as well. Her Side B, the Peach Bomber, has about enough time for you to get a soda, drink it and counter, but if it’s an extra large Dr. Pepper you might not make it in time to counter.
To deal damage to Peach, you must realize that she will be floating a good majority of the time. As such, you need to realize how to get her out of that state. A running Back Aerial or a Forward Aerial will knock her out of there, and eventually she’ll stop attempting that. Don’t be hesitant to counter in this match, seeing as how some of her attacks have some predictability to them. If she decided to go up high, bring her down with Aether for good damage and possibly a spike. Your jabs are, as always, very useful. Do be warned, however, that hers are just as fast, so you might want to shield if your jabs cancel each other out.
If you’re up to killing Peach, you’ll probably try either edgeguarding with Eruption, whose long charge time beats out Peach’s floatiness, Ftilt which can outrange her vastly and kill early, Up Smash to get her airdodges or just go for a spike, that always works. Peach is a light character, so against Ike it really doesn’t take too much. If you haven’t been using the Bair to get her out of the float state, go ahead and use that to kill her. As Peach doesn’t have anything especially fearsome to worry, go ahead and go for BF as your neutral of choice and then go with Corneria / Green Greens, depending on which one she bans. I’m sure you know by know how to take advantage of that stage. I recommend you avoid Rainbow Cruise, as she can exploit her great air game there.
Peach and Ike are more or less complete opposites, with the other having what the other lacks. As such, you’ll be trying to capitalize on the things that you have more than ever, especially your range and power. Being able to do this and avoid Peach’s good traits will serve you well.