diff --git a/spacy/cli/debug_data.py b/spacy/cli/debug_data.py
index 5d326f841..7264fc56a 100644
--- a/spacy/cli/debug_data.py
+++ b/spacy/cli/debug_data.py
@@ -673,35 +673,34 @@ def debug_data(
 
     if "trainable_lemmatizer" in factory_names:
         msg.divider("Trainable Lemmatizer")
-        # NOTE: label_list is the string version of the trees
-        label_list: Set[str] = gold_train_data["lemmatizer_trees"]
+        trees_train: Set[str] = gold_train_data["lemmatizer_trees"]
+        trees_dev: Set[str] = gold_dev_data["lemmatizer_trees"]
 
-        # NOTE: label_list_full is the set of strigified trees from
-        # iterating through all trees after all lemmas have been added
-        label_list_full: Set[str] = gold_train_data["lemmatizer_trees_full"]
-
-        # NOTE: model_labels is the tree IDs from iterating through the tree_id
-        # values in the component.
-        model_labels = _get_labels_from_trainable_lemmatizer(nlp)
-
-        msg.info(
-            f"{len(label_list)} label(s) in train data (created from trees.add and trees.tree_to_str)"
-        )
-        msg.info(
-            f"{len(label_list_full)} label(s) in train data (from iterating through tree_id)"
-        )
-        msg.info(
-            f"{len(model_labels)} label(s) in component (from iterating through tree_id on component.trees"
-        )
-
-        labels = set(label_list)
-        missing_labels = model_labels - labels
-
-        if missing_labels:
+        if gold_train_data["n_low_cardinality_lemmas"] > 0:
             msg.warn(
-                f"{len(missing_labels)} label(s) in model (component.tree)"
-                " and not present in the train data (trees.add and trees.tree_to_str)."
+                f"{gold_train_data['n_low_cardinality_lemmas']} docs with 1 or 0 unique lemmas."
             )
+        else:
+            msg.good("Training docs have sufficient unique lemmas")
+
+        train_not_dev = trees_train - trees_dev
+        if len(train_not_dev) != 0:
+            msg.warn(f"{len(train_not_dev)} labels were found only in the train data.")
+        else:
+            msg.good("Training data contains all lemmatizer trees in dev set.")
+
+        if gold_train_data["n_low_cardinality_lemmas"] > 0:
+            msg.warn(
+                f"{gold_dev_data['n_low_cardinality_lemmas']} docs with 1 or 0 unique lemmas."
+            )
+        else:
+            msg.good("Dev docs have sufficient unique lemmas")
+
+        dev_not_train = trees_dev - trees_train
+        if len(dev_not_train) != 0:
+            msg.warn(f"{len(dev_not_train)} labels were found only in the dev data.")
+        else:
+            msg.good("Trees in dev data present in training data.")
 
     msg.divider("Summary")
     good_counts = msg.counts[MESSAGES.GOOD]
@@ -765,9 +764,10 @@ def _compile_gold(
         "n_cats_bad_values": 0,
         "texts": set(),
         "lemmatizer_trees": set(),
-        "lemmatizer_trees_full": set(),
+        "n_low_cardinality_lemmas": 0,
     }
-    trees = EditTrees(nlp.vocab.strings)
+    if "trainable_lemmatizer" in factory_names:
+        trees = EditTrees(nlp.vocab.strings)
     for eg in examples:
         gold = eg.reference
         doc = eg.predicted
@@ -898,19 +898,16 @@ def _compile_gold(
             if nonproj.contains_cycle(aligned_heads):
                 data["n_cycles"] += 1
         if "trainable_lemmatizer" in factory_names:
-            # NOTE: From EditTreeLemmatizer._labels_from_data
-            for token in eg.reference:
+            # from EditTreeLemmatizer._labels_from_data
+            lemma_set = set()
+            for token in gold:
+                lemma_set.add(token.lemma)
                 if token.lemma != 0:
                     tree_id = trees.add(token.text, token.lemma_)
                     tree_str = trees.tree_to_str(tree_id)
                     data["lemmatizer_trees"].add(tree_str)
-    if "trainable_lemmatizer" in factory_names:
-        # After the edittree is built, let's try and capture all the
-        # string trees in that structure
-        all_trees = set()
-        for tree_id in range(len(trees)):
-            all_trees.add(trees.tree_to_str(tree_id))
-        data["lemmatizer_trees_full"] = all_trees
+            if len(lemma_set) < 2:
+                data["n_low_cardinality_lemmas"] += 1
     return data
 
 
@@ -1013,7 +1010,8 @@ def _get_labels_from_trainable_lemmatizer(nlp: Language) -> Set[str]:
     labels: Set[str] = set()
     for pipe_name in pipe_names:
         pipe = nlp.get_pipe(pipe_name)
-        for tree_id in range(len(pipe.trees)):
+        # This gets lemmatization trees and no partial subtrees
+        for tree_id in pipe.tree2label.keys():
             labels.add(pipe.trees.tree_to_str(tree_id))
     return labels