Have the characters truly aged by the end of the show?

Ok now in the Rugrats TV series we all know that Tommy is age 1, as well as Phil and Lil who are only three months older than Tommy, Chuckie is 2, Angelica and Susie are 3, Kimi is one and turns 2 in the last episode "Kimi Takes the Cake," and Dil is only a couple of months old. But if you watch the show closely, Angelica turns 4 in the season 3 episode "Angelica's Birthday," even though it's stated that she's 3 in the rest of the show, but it's possible that the episode doesn't happen later on until just before Dil is born. Meanwhile Tommy stated that in part three of the special "Acorn Nuts and Diapey Butts" which takes place just before the second movie "Rugrats In Paris," that for his birthday he really wanted a Reptar doll and because of that he thinks Grandpa Lou moved away for good, but if you remember in the first episode "Tommy's first birthday," that Reptar was never seen or mentioned and not introduced until a few episodes later "At the Movies." Because Tommy was only interested in eating dog food for his first birthday. Which means he's 2 in "Acorn Nuts and Diapey Butts" as well as Phil and Lil. Finally in the last episode of the show, "Kimi Takes the Cake," while it's stated she turns 2, it's more than likely she turned 3 because she's six months younger than Chuckie, while Kira states in the second Rugrats movie "Rugrats In Paris" she'd almost be two like Chuckie, but Chaz and Kira don't get married for another six months as stated, which happened in the season 8 episode "Bow Wow Wedding Vows." It seems very likely that all this information could not be true but I would like people's opinions on this!